TWM581322U - Improved structure of modulation laser diode - Google Patents

Abstract

A modulated laser diode improved structure comprising a semiconductor substrate and a distributed feedback laser. The distributed feedback laser system is formed on the semiconductor substrate, and the distributed feedback laser is divided into a front end portion and a rear end portion, and the distributed feedback laser includes a lower semiconductor layer, an active layer, an upper semiconductor layer, and a A front end diffraction grating and a first back end diffraction grating. The lower semiconductor layer is formed over the semiconductor substrate. An active layer is formed over the lower semiconductor layer. The upper semiconductor layer is formed over the active layer. The front-end diffraction grating is formed in the semiconductor layer below the front portion of the distributed feedback laser or in the upper semiconductor layer. The front end diffraction grating has a front end diffraction grating length. The front-end diffraction grating has a front-end diffraction grating period and a front-end diffraction grating duty cycle. The first back-end diffraction grating is formed in the semiconductor layer below the end of the distributed feedback laser or in the upper semiconductor layer. The first back end diffraction grating has a first back end diffraction grating length. The first back end diffraction grating has a first back end diffraction grating period and a first back end diffraction grating duty cycle. The length of the front end diffraction grating is greater than or equal to the length of the first back end diffraction grating. The front-end diffraction grating period is equal to the first back-end diffraction grating period. The front-end diffraction grating duty cycle is greater than or equal to 40% and less than or equal to 60%. The first back-end diffraction grating duty cycle (1) is greater than 0% and less than 40%, or (2) is greater than 60% and less than 100%.

Description

Modulated laser diode improved structure

This creation relates to a modulated laser diode, especially a modulated laser diode having an anti-reflective structure.

Please refer to FIG. 6, which is a specific embodiment of a modulated laser diode of the prior art. The modulated laser diode system of the prior art is an electroabsorption modulation laser (EML) diode comprising a semiconductor substrate 90, a distributed feedback laser, and an electro-optic light. An absorption absorber 96 (EAM: Electroabsorption Modulator), an anti-reflection coating 94, and a high reflection coating 95 are provided. The distributed feedback laser 9 and the electro-optic absorption modulator 96 are formed on the semiconductor substrate 90. The distributed feedback laser 9 includes an n-type semiconductor layer 91, an active layer 92, a p-type semiconductor layer 93, and a diffraction grating 97. The n-type semiconductor layer 91 is formed on the semiconductor substrate 90; the active layer 92 is formed on the n-type semiconductor layer 91; and the p-type semiconductor layer 93 is formed on the active layer 92. The diffraction grating 97 is formed in the p-type semiconductor layer 93. The anti-reflection film 94 is formed at the front end of the electro-optic absorption modulating device 96. A highly reflective film 95 is formed at the rear end of the distributed feedback laser 9. The diffraction grating 97 has a diffraction grating period P9 and a diffraction grating duty cycle D9/P9 (duty cycle). The diffraction grating duty cycle D9/P9 is equal to 50%. In the design of the modulated laser diode of the prior art, the laser light is output from the front end of the electro-optic absorption modulator 96. Although the anti-reflection film 94 at the front end of the electro-optic absorption modulating device 96 can suppress the reflection of the laser light, a small portion of the laser light is reflected back to the electro-optic absorption modulator 96 and the distributed feedback ray. Shot 9, and then reflected by the high-reflection film 95 at the rear end of the distributed feedback laser 9 back to the distributed feedback laser 9 and the electro-optic absorption modulator 96, thereby causing the output power of the laser light to fluctuate with time. (See Figure 2M later).

In view of this, the creator has developed a simple assembly design, which can avoid the above-mentioned shortcomings, is easy to install, and has the advantages of low cost, and takes into account the considerations of flexibility and economy.

The technical problem to be solved by this creation is how to effectively reduce the amplitude of the laser light output power of the modulated laser diode over time.

In order to solve the aforementioned problems in order to achieve the desired effect, the present invention provides a modified laser diode improved structure including a semiconductor substrate and a distributed feedback laser. The distributed feedback laser system is formed on the semiconductor substrate. The distributed feedback laser is divided into a front end portion and a rear end portion. The distributed feedback laser includes a lower semiconductor layer, an active layer, an upper semiconductor layer, a front end diffraction grating, and a first back end diffraction grating. The lower semiconductor layer is formed on the semiconductor substrate; the lower semiconductor layer is formed on the semiconductor substrate; and the upper semiconductor layer is formed on the active layer. Wherein the front-end diffraction grating is formed in the semiconductor layer or in the upper semiconductor layer below the front end of the distributed feedback laser, the front-end diffraction grating has a front-end diffraction grating length, and the front-end diffraction grating has a front-end diffraction grating period. And a front-end diffraction grating duty cycle. The first back-end diffraction grating is formed in the semiconductor layer or in the upper semiconductor layer below the end of the distributed feedback laser, and the first back-end diffraction grating has a first back-end diffraction grating length. The first back end diffraction grating has a first back end diffraction grating period and a first back end diffraction grating duty cycle. The length of the front-end diffraction grating is greater than or equal to the length of the first back-end diffraction grating, and the front-end diffraction grating period is equal to the first back-end diffraction grating period, and the front-end diffraction grating duty period is greater than or equal to 40% and less than or Equal to 60%, the first back-end diffraction grating duty cycle (1) is greater than 0% and less than 40%, or (2) is greater than 60% and less than 100%. Thereby, the amplitude of the laser light output power of the modulated laser diode of the present invention is effectively reduced with time.

In one embodiment, wherein the distance between the front end diffraction grating and the active layer is equal to a distance between the first back end diffraction grating and the active layer.

In an embodiment, wherein (1) the front-end diffraction grating is formed in the semiconductor layer below the front end of the distributed feedback laser, and the first back-end diffraction grating is formed at the end after the distributed feedback laser In the upper semiconductor layer, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the semiconductor layer below the end of the distributed feedback laser, or 2) The front-end diffraction grating is formed in the semiconductor layer above the front end of the distributed feedback laser, and the first back-end diffraction grating is formed in the semiconductor layer below the end of the distributed feedback laser, wherein the distribution The feedback laser further includes a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the semiconductor layer above the end of the distributed feedback laser; wherein the second back-end diffraction grating and the active One of the distances between the layers is equal to the distance between the front end diffraction grating and the active layer, wherein the second rear end diffraction grating has a second rear end diffraction grating length, wherein the second rear end diffraction grating has a first Two back-end diffraction grating periods and one a second back-end diffraction grating duty cycle, wherein the second back-end diffraction grating length is equal to the first back-end diffraction grating length, wherein the front-end diffraction grating period is equal to the second back-end diffraction grating period, wherein the second rear The end diffraction grating duty cycle is equal to 100%.

In one embodiment, wherein the distance between the front end diffraction grating and the active layer is less than a distance between the first back end diffraction grating and the active layer.

In an embodiment, wherein (1) the front-end diffraction grating is formed in the semiconductor layer above the front end of the distributed feedback laser, and the first back-end diffraction grating is formed at the end after the distributed feedback laser In the upper semiconductor layer, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the semiconductor layer above the end of the distributed feedback laser, and The second back-end diffraction grating is located between the first back-end diffraction grating and the active layer; (2) the front-end diffraction grating is formed in the semiconductor layer above the front end of the distributed feedback laser, and the first back end The diffraction grating is formed in the semiconductor layer below the end of the distributed feedback laser, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the distributed Retrieving the semiconductor layer above the end after the laser; (3) the front-end diffraction grating is formed in the semiconductor layer below the front end of the distributed feedback laser, and the first back-end diffraction grating is formed in the distributed feedback In the semiconductor layer below the end of the laser, The distributed feedback laser further includes a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the semiconductor layer below the end of the distributed feedback laser, and the second back-end diffraction grating system Between the first back-end diffraction grating and the active layer; or (4) the front-end diffraction grating is formed in the semiconductor layer below the front end of the distributed feedback laser, and the first back-end diffraction grating is formed on Distributed feedback laser after the end of the semiconductor layer, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed at the end of the distributed feedback laser In the lower semiconductor layer; wherein a distance between the second back-end diffraction grating and the active layer is equal to a distance between the front-end diffraction grating and the active layer, wherein the second back-end diffraction grating has a second back end Diffraction grating length, wherein the second back-end diffraction grating has a second back-end diffraction grating period and a second back-end diffraction grating a duty cycle, wherein the second back-end diffraction grating length is equal to the first back-end diffraction grating length, wherein the front-end diffraction grating period is equal to the second back-end diffraction grating period, wherein the second back-end diffraction grating duty cycle The system is equal to 100%.

In an embodiment, wherein the first back-end diffraction grating duty cycle (1) is greater than 0% and less than or equal to 25%, or (2) is greater than or equal to 75% and less than 100%.

The present invention further provides a modified laser diode improved structure including a semiconductor substrate and a distributed feedback laser. The distributed feedback laser system is formed on the semiconductor substrate. The distributed feedback laser is divided into a front end portion and a rear end portion. The distributed feedback laser includes a lower semiconductor layer, an active layer, an upper semiconductor layer, a front end diffraction grating, and a first back end diffraction grating. The lower semiconductor layer is formed on the semiconductor substrate; the lower semiconductor layer is formed on the semiconductor substrate; and the upper semiconductor layer is formed on the active layer. Wherein the front-end diffraction grating is formed in the semiconductor layer or in the upper semiconductor layer below the front end of the distributed feedback laser, the front-end diffraction grating has a front-end diffraction grating length, and the front-end diffraction grating has a front-end diffraction grating period. And a front-end diffraction grating duty cycle. The first back-end diffraction grating is formed in the semiconductor layer below the end of the distributed feedback laser or in the upper semiconductor layer, and the first back-end diffraction grating has a first back-end diffraction grating length, first The back end diffraction grating has a first back end diffraction grating period and a first back end diffraction grating duty cycle. The length of the front-end diffraction grating is greater than or equal to the length of the first back-end diffraction grating, wherein the front-end diffraction grating period is equal to the first back-end diffraction grating period, wherein the front-end diffraction grating duty period is greater than or equal to 40% and Less than or equal to 60%, wherein a distance between the front end diffraction grating and the active layer is less than a distance between the first back end diffraction grating and the active layer. Thereby, the amplitude of the laser light output power of the modulated laser diode of the present invention is effectively reduced with time.

In an embodiment, wherein the first back-end diffraction grating duty cycle is greater than or equal to 40% and less than or equal to 60%.

In an embodiment, wherein (1) the front-end diffraction grating is formed in the semiconductor layer above the front end of the distributed feedback laser, and the first back-end diffraction grating is formed at the end after the distributed feedback laser In the upper semiconductor layer, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the semiconductor layer above the end of the distributed feedback laser, and The second back-end diffraction grating is located between the first back-end diffraction grating and the active layer; (2) the front-end diffraction grating is formed in the semiconductor layer above the front end of the distributed feedback laser, and the first back end The diffraction grating is formed in the semiconductor layer below the end of the distributed feedback laser, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the distributed Retrieving the semiconductor layer above the end after the laser; (3) the front-end diffraction grating is formed in the semiconductor layer below the front end of the distributed feedback laser, and the first back-end diffraction grating is formed in the distributed feedback In the semiconductor layer below the end of the laser, The distributed feedback laser further includes a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the semiconductor layer below the end of the distributed feedback laser, and the second back-end diffraction grating system Between the first back-end diffraction grating and the active layer; or (4) the front-end diffraction grating is formed in the semiconductor layer below the front end of the distributed feedback laser, and the first back-end diffraction grating is formed on Distributed feedback laser after the end of the semiconductor layer, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed at the end of the distributed feedback laser In the lower semiconductor layer; wherein a distance between the second back-end diffraction grating and the active layer is equal to a distance between the front-end diffraction grating and the active layer, wherein the second back-end diffraction grating has a second back end Diffraction grating length, wherein the second back-end diffraction grating has a second back-end diffraction grating period and a second back-end diffraction grating a duty cycle, wherein the second back-end diffraction grating length is equal to the first back-end diffraction grating length, wherein the front-end diffraction grating period is equal to the second back-end diffraction grating period, wherein the second back-end diffraction grating duty cycle The system is equal to 100%.

In one embodiment, the lower semiconductor layer is an n-type semiconductor layer.

In one embodiment, the upper semiconductor layer is a p-type semiconductor layer.

In one embodiment, the modulated laser diode system is a direct modulation laser diode.

In an embodiment, the method further includes an electro-optic absorption modulating device, wherein the electro-optic absorption modulating device is formed on the semiconductor substrate, wherein the distributed feedback laser is disposed at a position of the distributed feedback laser Between the end portion and the electro-optic absorption modulating device, wherein the modulated laser diode system is an electro-optic absorption modulated laser diode.

In an embodiment, wherein the ratio of the length of the front-end diffraction grating to the length of the first back-end diffraction grating is greater than or equal to 1, and less than or equal to four.

In order to further understand the present invention, the preferred embodiments of the present invention, together with the drawings and figure numbers, detail the specific components of the present creation and the effects achieved thereby.

1‧‧‧Distributed feedback laser

2‧‧‧ Distributed feedback before the end of the laser

3‧‧‧ Distributed feedback back to the end of the laser

4‧‧‧Electro-optic absorption modulator

10‧‧‧Semiconductor substrate

20‧‧‧ Lower semiconductor layer

30‧‧‧ active layer

40‧‧‧Upper semiconductor layer

50‧‧‧ front-end diffraction grating

51‧‧‧First back-end diffraction grating

52‧‧‧Second back-end diffraction grating

6‧‧‧Anti-reflective film

7‧‧‧High-reflection film

9‧‧‧Distributed feedback laser

90‧‧‧Semiconductor substrate

91‧‧‧n type semiconductor layer

92‧‧‧ active layer

93‧‧‧p-type semiconductor layer

94‧‧‧Anti-reflective film

95‧‧‧High-reflection film

96‧‧‧Electroluminescence absorption modulator

97‧‧‧Diffraction grating

D0/P0‧‧‧ front-end diffraction grating duty cycle

D1/P1‧‧‧ first back-end diffraction grating duty cycle

D2/P2‧‧‧second back-end diffraction grating duty cycle

D9/P9‧‧‧Diffraction grating duty cycle

L0‧‧‧ front-end diffraction grating length

L1‧‧‧ first back-end diffraction grating length

L2‧‧‧second back-end diffraction grating length

P0‧‧‧ front-end diffraction grating period

P1‧‧‧ first back-end diffraction grating period

P2‧‧‧second back-end diffraction grating period

P9‧‧‧Diffraction grating period

X0‧‧‧The distance between the front-end diffraction grating and the active layer

X1‧‧‧The distance between the first back-end diffraction grating and the active layer

X2‧‧‧The distance between the second back-end diffraction grating and the active layer

Fig. 1A is a schematic cross-sectional view showing a specific embodiment of a modified structure of a modulated laser diode.

FIG. 1B is a schematic cross-sectional view showing a specific embodiment of a modified structure of a modulated laser diode.

2A to 2L are the distributed backs of a modified laser diode modified structure. A schematic cross-sectional view of a specific embodiment of a laser feed.

The 2M figure is a comparison of the output power versus time of a specific embodiment of a modified laser diode modified structure and a specific embodiment of the prior art.

The 2N figure is a comparison of output power versus time for a specific embodiment of a modified laser diode modified structure.

3A to 3H are schematic cross-sectional views showing a specific embodiment of a distributed feedback laser for modifying a modified laser diode structure.

4A to 4H are schematic cross-sectional views showing a specific embodiment of a distributed feedback laser for modifying a modified laser diode structure.

5A to 5H are schematic cross-sectional views showing a specific embodiment of a distributed feedback laser for modifying a modified laser diode structure.

Figure 6 is a specific embodiment of a modulated laser diode of the prior art.

Please refer to FIG. 1A, which is a cross-sectional view showing a specific embodiment of a modified structure of a modulated laser diode. The modulated laser diode system of this embodiment is a direct modulation laser (DML) diode, comprising a semiconductor substrate 10, a distributed feedback laser 1, an anti-reflection film 6 and a Highly reflective film 7. The distributed feedback laser 1 is formed on the semiconductor substrate 10. The distributed feedback laser 1 is divided into a front end portion 2 and a rear end portion 3. The anti-reflection film 6 is formed at the front end of the end portion 2 before the distributed feedback laser 1; and the high reflection film 7 is formed at the rear end of the end portion 3 after the distributed feedback laser 1 is formed. The laser light is output from the front end of the front end 2 of the distributed feedback laser 1 . Please also refer to the 2A to 2L, 3A to 3H, 4A to 4H, and 5A to 5H to create a modulated laser diode. A schematic cross-sectional view of a specific embodiment of a distributed feedback laser of a bulk modified structure. The detailed structure of the distributed feedback laser 1 in the embodiment of FIG. 1A can be compared with the 2A to 2L, the 3A to 3H, the 4A to 4H, and the 5A. The structure of the distributed feedback laser 1 in any of the embodiments of FIG. 5H is the same.

Please refer to FIG. 1B, which is a schematic cross-sectional view showing a specific embodiment of a modified structure of a modulated laser diode. The modulated laser diode system of this embodiment is an electro-optic absorption modulated laser diode, comprising a semiconductor substrate 10, a distributed feedback laser, an electro-optic absorption modulator 4, and a The anti-reflection film 6 and a highly reflective film 7 are provided. The distributed feedback laser 1 and the electro-optic absorption modulator 4 are formed on the semiconductor substrate 10. The distributed feedback laser 1 is divided into a front end portion 2 and a rear end portion 3. The front end 2 of the distributed feedback laser 1 is located between the end 3 of the distributed feedback laser 1 and the electro-optic absorption modulator 4. The anti-reflection film 6 is formed at the front end of the electro-optic absorption modulating device 4; and the high-reflection film 7 is formed at the rear end of the end portion 3 after the distributed feedback laser 1 is formed. The laser light is output from the front end of the electro-optic absorption modulator 4. Please also refer to the distribution of the modified structure of the modulated laser diode in the 2A to 2L, 3A to 3H, 4A to 4H, and 5A to 5H. A schematic cross-sectional view of a specific embodiment of a feedback laser. The detailed structure of the distributed feedback laser 1 in the embodiment of FIG. 1B can be compared with the 2A to 2L, the 3A to 3H, the 4A to 4H, and the 5A. The structure of the distributed feedback laser 1 in any of the embodiments of FIG. 5H is the same.

Please refer to FIG. 2A, which is a cross-sectional view of a specific embodiment of a distributed feedback laser for modifying a modified laser diode. In this embodiment, a modulated laser diode modification structure of the present invention includes a semiconductor substrate 10 and a distributed feedback laser 1. The distributed feedback laser 1 is formed on the semiconductor substrate 10. Distributed feedback laser 1 It is divided into a front end portion 2 and a rear end portion 3. The distributed feedback laser 1 includes a lower semiconductor layer 20, an active layer 30, an upper semiconductor layer 40, a front end diffraction grating 50, and a first rear end diffraction grating 51. The lower semiconductor layer 20 is formed over the semiconductor substrate 10, wherein the lower semiconductor layer 20 is an n-type semiconductor layer. The active layer 30 is formed over the lower semiconductor layer 20. The upper semiconductor layer 40 is formed over the active layer 30, wherein the upper semiconductor layer 40 is a p-type semiconductor layer. The front end diffraction grating 50 is formed in the semiconductor layer 40 above the front end 2 of the distributed feedback laser 1 , wherein the front end diffraction grating 50 has a front end diffraction grating length L0, wherein the front end diffraction grating 50 has a front end winding The grating period P0 and a front-end diffraction grating duty cycle D0/P0. The first back-end diffraction grating 51 is formed in the semiconductor layer 40 above the end portion 3 after the distributed feedback laser 1 . The first rear end diffraction grating 51 has a first rear end diffraction grating length L1. The first rear end diffraction grating 51 has a first rear end diffraction grating period P1 and a first rear end diffraction grating duty period D1/P1. One of the distances X0 between the front end diffraction grating 50 and the active layer 30 is equal to a distance X1 between the first rear end diffraction grating 51 and the active layer 30. The front end diffraction grating length L0 is greater than the first rear end diffraction grating length L1. The front end diffraction grating period P0 is equal to the first back end diffraction grating period P1. The front-end diffraction grating duty cycle D0/P0 is greater than or equal to 40% and less than or equal to 60%. The first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than 40%. The front-end diffraction grating duty cycle D0/P0 is not equal to the first back-end diffraction grating duty cycle D1/P1. In the embodiment of FIG. 1A or FIG. 1B, a modified laser diode modified structure can have the structure of the distributed feedback laser 1 as shown in FIG. 2A, thereby effectively reducing the modulation. The amplitude of the laser light output power of the laser diode over time. In some embodiments, the front end diffraction grating length L0 is equal to the first rear end diffraction grating length L1. In other embodiments, wherein the ratio of the front end diffraction grating length L0 to the first rear end diffraction grating length L1 is greater than or equal to 1, and less than or equal to four. In some embodiments, after the first The end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 35%. In other embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 30%. In some preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 25%. In still other preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 23%. In some preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 20%. In still other preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 18%. In some preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 15%. In still other preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 10%. In some preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 5%.

Please refer to FIG. 2M and FIG. 2N, which are comparisons of the output power versus time of a specific embodiment of a modified laser diode modified structure and a specific embodiment of the prior art. In the second embodiment of FIG. 2 and the embodiment of the second embodiment, a modified laser diode modified structure is an electro-optic absorption modulated laser diode, and the structure is as shown in the embodiment of FIG. 1B. The structure of the distributed feedback laser 1 is as shown in FIG. 2A. In the 2M picture, there is a special case in which the structure of the first back-end diffraction grating duty cycle D1/P1 is equal to 50% has the same structure as the diffraction grating 97 of the prior art. In the 2M picture, the first back-end diffraction grating duty cycle D1/P1 is equal to 40%, 30%, or 20%, which is the structure of the distributed feedback laser 1 of the present invention. It can be easily observed from the 2M picture that when the first back-end diffraction grating duty cycle D1/P1 is equal to 50% (having the same structure as the diffraction grating 97 of the prior art), the output power of the laser light is time-dependent. The shock is very large. And the distributed feedback laser 1 of this creation has the structure (regardless of Is the first back-end diffraction grating duty cycle D1/P1 is equal to 40%, D1=30%, or D1=20%), and the output power of the laser light with the amplitude of the oscillation is significantly smaller than the first back-end diffraction grating. The duty cycle D1/P1 is equal to 50% (the same structure as the conventional diffraction grating 97), and the output power is oscillated over time. Especially when the first back-end diffraction grating duty cycle D1/P1 is equal to 20%, the output power of the laser light with time is much smaller than the first back-end diffraction grating duty cycle D1/P1 is equal to 50% ( The output power of the same structure as the diffraction grating 97 of the prior art has an amplitude of oscillation with time. Since when the first back-end diffraction grating duty cycle D1/P1 is equal to 10%, or 5%, the output power of the laser light is too small with time, and if it is placed in the 2M picture, the difference will not be seen. Therefore, it is displayed in the 2Nth picture. It can be clearly seen from the 2NN map that the first back-end diffraction grating duty cycle D1/P1 is equal to 10%, or 5% of the output power with time is larger than the first back-end diffraction grating duty cycle D1/P1. The 20% output power has a smaller amplitude with time. Therefore, the modified structure of the modulated laser diode of the present invention can enhance the anti-reflection function and significantly reduce the amplitude of the light output power with time. The second NN has a special case where the first back-end diffraction grating duty cycle D1/P1 is equal to 0%, which is indicated as the absence of the first back-end diffraction grating 51. However, without the first back-end diffraction grating 51, the output power has a larger amplitude of oscillation with time than the first back-end diffraction grating duty cycle D1/P1 equals 20%, 10%, or 5% of the output power with time. The magnitude of the shock.

Please refer to FIG. 2B, which is a cross-sectional view of a specific embodiment of a distributed feedback laser for modifying a modified laser diode structure. The main structure of the embodiment of FIG. 2B is substantially the same as the structure of the embodiment of FIG. 2A, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. In some embodiments, the first back end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 65%. In other embodiments, the first The back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 70%. In some preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 75%. In still other preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 77%. In some preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 80%. In other preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 82%. In some preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 85%. In still other preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 90%. In some preferred embodiments, the first back-end diffraction grating duty cycle D1/P1 is greater than 0% and less than or equal to 95%. In the embodiment of FIG. 1A or FIG. 1B, a modified laser diode modified structure may have a structure of a distributed feedback laser 1 as shown in FIG. 2B, thereby effectively reducing the modulated thunder The amplitude of the laser light output power of the diode is oscillated over time.

Please refer to FIG. 2C to FIG. 2L, which are schematic cross-sectional views of a specific embodiment of a distributed feedback laser for modifying a modified laser diode. The main structure of the embodiment of FIG. 2C is substantially the same as the structure of the embodiment of FIG. 2A, except that the first back-end diffraction grating 51 is formed on the semiconductor under the end portion 3 after the distributed feedback laser 1 In layer 20, and wherein the distance X0 between the front end diffraction grating 50 and the active layer 30 is equal to the distance X1 between the first rear end diffraction grating 51 and the active layer 30. The main structure of the embodiment of FIG. 2D is substantially the same as the structure of the embodiment of FIG. 2C, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of FIG. 2E is substantially the same as that of the embodiment of FIG. 2A except that the front end diffraction grating 50 is formed in the semiconductor layer 20 below the end portion 2 of the distributed feedback laser 1. And wherein the distance between the front end diffraction grating 50 and the active layer 30 is X0, etc. A distance X1 between the grating grating 51 and the active layer 30 at the first rear end. The main structure of the embodiment of FIG. 2F is substantially the same as the structure of the embodiment of FIG. 2E, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of the 2Gth diagram is substantially the same as the embodiment of the embodiment of FIG. 2E, except that the first back-end diffraction grating 51 is formed on the semiconductor under the end portion 3 after the distributed feedback laser 1 In layer 20, and wherein the distance X0 between the front end diffraction grating 50 and the active layer 30 is equal to the distance X1 between the first rear end diffraction grating 51 and the active layer 30. The main structure of the embodiment of FIG. 2H is substantially the same as the structure of the embodiment of FIG. 2G, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of FIG. 2I is substantially the same as that of the embodiment of FIG. 2C, except that the distributed feedback laser 1 further includes a second back-end diffraction grating 52. The second back-end diffraction grating 52 is formed in the semiconductor layer 40 above the end portion 3 after the distributed feedback laser 1 . A distance X2 between the second back-end diffraction grating 52 and the active layer 30 is equal to the distance X0 between the front-end diffraction grating 50 and the active layer 30. The second rear end diffraction grating 52 has a second rear end diffraction grating length L2. The second back end diffraction grating 52 has a second back end diffraction grating period P2 and a second back end diffraction grating duty cycle D2/P2. The second back-end diffraction grating length L2 is equal to the first back-end diffraction grating length L1. The front end diffraction grating period P0 is equal to the second rear end diffraction grating period P2. The second back-end diffraction grating duty cycle D2/P2 is equal to 100%. The main structure of the embodiment of FIG. 2J is substantially the same as the structure of the embodiment of FIG. 2I, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of FIG. 2K is substantially the same as that of the embodiment of FIG. 2E, except that the distributed feedback laser 1 further includes a second back-end diffraction grating 52. The second back-end diffraction grating 52 is formed in the semiconductor layer 20 below the end portion 3 after the distributed feedback laser 1 . One distance between the second back-end diffraction grating 52 and the active layer 30, X2, etc. The distance between the front end diffraction grating 50 and the active layer 30 is X0. The second rear end diffraction grating 52 has a second rear end diffraction grating length L2. The second back end diffraction grating 52 has a second back end diffraction grating period P2 and a second back end diffraction grating duty cycle D2/P2. The second back-end diffraction grating length L2 is equal to the first back-end diffraction grating length L1. The front end diffraction grating period P0 is equal to the second rear end diffraction grating period P2. The second back-end diffraction grating duty cycle D2/P2 is equal to 100%. The main structure of the embodiment of the second embodiment is substantially the same as the embodiment of the embodiment of FIG. 2K, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. In the embodiment of FIG. 1A or FIG. 1B, a modified laser diode modified structure may have a structure of a distributed feedback laser 1 according to any one of the second to second embodiments. Thereby, the oscillation amplitude of the laser light output power of the modulated laser diode can be effectively reduced with time.

Please refer to FIG. 3A to FIG. 3H, which are schematic cross-sectional views of a specific embodiment of a distributed feedback laser for modifying a modified laser diode. The main structure of the embodiment of FIG. 3A is substantially the same as that of the embodiment of FIG. 2A, except that the distance X0 between the front end diffraction grating 50 and the active layer 30 is smaller than the first rear end diffraction grating 51. The distance X1 from the active layer 30. The main structure of the embodiment of FIG. 3B is substantially the same as the structure of the embodiment of FIG. 3A, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of FIG. 3C is substantially the same as the structure of the embodiment of FIG. 2C, except that the distance X0 between the front end diffraction grating 50 and the active layer 30 is smaller than the first rear end diffraction grating 51. The distance X1 from the active layer 30. The main structure of the embodiment of the 3D figure is substantially the same as the structure of the embodiment of FIG. 3C, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of FIG. 3E is substantially the same as the structure of the embodiment of FIG. 2E, except that the distance between the front end diffraction grating 50 and the active layer 30 is X0 is smaller than the distance X1 between the first back-end diffraction grating 51 and the active layer 30. The main structure of the embodiment of FIG. 3F is substantially the same as the structure of the embodiment of FIG. 3E, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of the 3Gth diagram is substantially the same as that of the embodiment of the 2Gth diagram, except that the distance X0 between the front end diffraction grating 50 and the active layer 30 is smaller than that of the first rear end diffraction grating 51. The distance X1 from the active layer 30. The main structure of the embodiment of FIG. 3H is substantially the same as the embodiment of the embodiment of FIG. 3G, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. In the embodiment of FIG. 1A or FIG. 1B, a modified laser diode modified structure may have a structure of distributed feedback laser 1 according to any one of FIGS. 3A to 3H. Thereby, the oscillation amplitude of the laser light output power of the modulated laser diode can be effectively reduced with time.

Please refer to FIG. 4A to FIG. 4H, which are schematic cross-sectional views of a specific embodiment of a distributed feedback laser for modifying a modified laser diode. The main structure of the embodiment of FIG. 4A is substantially the same as that of the embodiment of FIG. 3A, except that the distributed feedback laser 1 further includes a second back-end diffraction grating 52. The second back-end diffraction grating 52 is formed in the semiconductor layer 40 above the end portion 3 after the distributed feedback laser 1 . A distance X2 between the second back-end diffraction grating 52 and the active layer 30 is equal to the distance X0 between the front-end diffraction grating 50 and the active layer 30. The second rear end diffraction grating 52 has a second rear end diffraction grating length L2. The second back end diffraction grating 52 has a second back end diffraction grating period P2 and a second back end diffraction grating duty cycle D2/P2. The second back-end diffraction grating length L2 is equal to the first back-end diffraction grating length L1. The front end diffraction grating period P0 is equal to the second rear end diffraction grating period P2. The second back-end diffraction grating duty cycle D2/P2 is equal to 100%. The main structure of the embodiment of FIG. 413 is substantially the same as the structure of the embodiment of FIG. 4A, except that the first back-end diffraction grating duty cycle D1/P1 The system is greater than 60% and less than 100%. The main structure of the embodiment of FIG. 4C is substantially the same as that of the embodiment of FIG. 3C, except that the distributed feedback laser 1 further includes a second back-end diffraction grating 52. The second back-end diffraction grating 52 is formed in the semiconductor layer 40 above the end portion 3 after the distributed feedback laser 1 . A distance X2 between the second back-end diffraction grating 52 and the active layer 30 is equal to the distance X0 between the front-end diffraction grating 50 and the active layer 30. The second rear end diffraction grating 52 has a second rear end diffraction grating length L2. The second back end diffraction grating 52 has a second back end diffraction grating period P2 and a second back end diffraction grating duty cycle D2/P2. The second back-end diffraction grating length L2 is equal to the first back-end diffraction grating length L1. The front end diffraction grating period P0 is equal to the second rear end diffraction grating period P2. The second back-end diffraction grating duty cycle D2/P2 is equal to 100%. The main structure of the embodiment of FIG. 4D is substantially the same as the structure of the embodiment of FIG. 4C, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of FIG. 4E is substantially the same as the embodiment of the embodiment of FIG. 3E, except that the distributed feedback laser 1 further includes a second back-end diffraction grating 52. The second back-end diffraction grating 52 is formed in the semiconductor layer 20 below the end portion 3 after the distributed feedback laser 1 . A distance X2 between the second back-end diffraction grating 52 and the active layer 30 is equal to the distance X0 between the front-end diffraction grating 50 and the active layer 30. The second rear end diffraction grating 52 has a second rear end diffraction grating length L2. The second back end diffraction grating 52 has a second back end diffraction grating period P2 and a second back end diffraction grating duty cycle D2/P2. The second back-end diffraction grating length L2 is equal to the first back-end diffraction grating length L1. The front end diffraction grating period P0 is equal to the second rear end diffraction grating period P2. The second back-end diffraction grating duty cycle D2/P2 is equal to 100%. The main structure of the embodiment of FIG. 4F is substantially the same as the structure of the embodiment of FIG. 4E, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. The main structure of the embodiment of FIG. 4G and the 3G The embodiment of the figure is substantially identical in construction, except that the distributed feedback laser 1 further includes a second back-end diffraction grating 52. The second back-end diffraction grating 52 is formed in the semiconductor layer 20 below the end portion 3 after the distributed feedback laser 1 . A distance X2 between the second back-end diffraction grating 52 and the active layer 30 is equal to the distance X0 between the front-end diffraction grating 50 and the active layer 30. The second rear end diffraction grating 52 has a second rear end diffraction grating length L2. The second back end diffraction grating 52 has a second back end diffraction grating period P2 and a second back end diffraction grating duty cycle D2/P2. The second back-end diffraction grating length L2 is equal to the first back-end diffraction grating length L1. The front end diffraction grating period P0 is equal to the second rear end diffraction grating period P2. The second back-end diffraction grating duty cycle D2/P2 is equal to 100%. The main structure of the embodiment of FIG. 4H is substantially the same as the structure of the embodiment of FIG. 4G, except that the first back-end diffraction grating duty cycle D1/P1 is greater than 60% and less than 100%. In the embodiment of FIG. 1A or FIG. 1B, a modified laser diode modified structure may have a structure of distributed feedback laser 1 according to any one of FIGS. 4A to 4H. Thereby, the oscillation amplitude of the laser light output power of the modulated laser diode can be effectively reduced with time.

Please refer to FIG. 5A to FIG. 5H, which are schematic cross-sectional views of a specific embodiment of a distributed feedback laser for modifying a modified laser diode. The main structure of the embodiment of FIG. 5A is substantially the same as the structure of the embodiment of FIG. 3A, except that the first back-end diffraction grating duty cycle D1/P1 is greater than or equal to 40% and less than or equal to 60%. . The main structure of the embodiment of FIG. 5B is substantially the same as the structure of the embodiment of FIG. 3C, except that the first back-end diffraction grating duty cycle D1/P1 is greater than or equal to 40% and less than or equal to 60%. . The main structure of the embodiment of FIG. 5C is substantially the same as the structure of the embodiment of FIG. 3E, except that the first back-end diffraction grating duty cycle D1/P1 is greater than or equal to 40% and less than or equal to 60%. . The main structure of the embodiment of the 5D figure is substantially the same as the structure of the embodiment of the 3G figure, but The first back-end diffraction grating duty cycle D1/P1 is greater than or equal to 40% and less than or equal to 60%. The main structure of the embodiment of FIG. 5E is substantially the same as that of the embodiment of FIG. 5A, except that the distributed feedback laser 1 further includes a second back-end diffraction grating 52. The second back-end diffraction grating 52 is formed in the semiconductor layer 40 above the end portion 3 after the distributed feedback laser 1 . A distance X2 between the second back-end diffraction grating 52 and the active layer 30 is equal to the distance X0 between the front-end diffraction grating 50 and the active layer 30. The second rear end diffraction grating 52 has a second rear end diffraction grating length L2. The second back end diffraction grating 52 has a second back end diffraction grating period P2 and a second back end diffraction grating duty cycle D2/P2. The second back-end diffraction grating length L2 is equal to the first back-end diffraction grating length L1. The front end diffraction grating period P0 is equal to the second rear end diffraction grating period P2. The second back-end diffraction grating duty cycle D2/P2 is equal to 100%. The main structure of the embodiment of FIG. 5F is substantially the same as the structure of the embodiment of FIG. 5E, except that the first back-end diffraction grating 51 is formed under the distributed feedback laser 1 and the semiconductor under the end 3 In the layer 20, and wherein the distance X0 between the front end diffraction grating 50 and the active layer 30 is smaller than the distance X1 between the first rear end diffraction grating 51 and the active layer 30. The main structure of the embodiment of the 5Gth embodiment is substantially the same as the embodiment of the embodiment of FIG. 5C, except that the distributed feedback laser 1 further includes a second back-end diffraction grating 52. The second back-end diffraction grating 52 is formed in the semiconductor layer 20 below the end portion 3 after the distributed feedback laser 1 . A distance X2 between the second back-end diffraction grating 52 and the active layer 30 is equal to the distance X0 between the front-end diffraction grating 50 and the active layer 30. The second rear end diffraction grating 52 has a second rear end diffraction grating length L2. The second back end diffraction grating 52 has a second back end diffraction grating period P2 and a second back end diffraction grating duty cycle D2/P2. The second back-end diffraction grating length L2 is equal to the first back-end diffraction grating length L1. The front end diffraction grating period P0 is equal to the second rear end diffraction grating period P2. The second back-end diffraction grating duty cycle D2/P2 is equal to 100%. Where 5H The main structure of the embodiment of the figure is substantially the same as that of the embodiment of FIG. 5G, except that the first back-end diffraction grating 51 is formed in the semiconductor layer 20 below the end portion 3 after the distributed feedback laser 1 And wherein the distance X0 between the front end diffraction grating 50 and the active layer 30 is smaller than the distance X1 between the first rear end diffraction grating 51 and the active layer 30. In the embodiment of FIG. 1A or FIG. 1B, a modified laser diode modified structure may have a structure of a distributed feedback laser 1 according to any one of the fifth to fifth embodiments. Thereby, the oscillation amplitude of the laser light output power of the modulated laser diode can be effectively reduced with time.

The foregoing is a specific embodiment of the present invention and the technical means employed, and many variations and modifications can be derived therefrom based on the disclosure or teachings herein, and can still be regarded as equivalent changes made by the inventive concept. The role of the spirit and the spirit of the text and the scope of the text should be considered within the technical scope of this creation.

In summary, according to the content disclosed above, this creation can indeed achieve the intended purpose of creation, providing a modified structure of modulated laser diodes, which is highly priced in the industry, and proposes to create patent applications according to law. .

Claims (20)

A modulated laser diode improved structure includes: a semiconductor substrate; and a distributed feedback laser formed on the semiconductor substrate, wherein the distributed feedback laser is divided into a front end portion and a rear end portion The distributed feedback laser includes: a lower semiconductor layer formed on the semiconductor substrate; an active layer formed on the lower semiconductor layer; and an upper semiconductor layer formed on the active layer a front-end diffraction grating formed in the lower semiconductor layer or the upper semiconductor layer of the front end portion of the distributed feedback laser, wherein the front-end diffraction grating has a front-end diffraction grating length, wherein The front-end diffraction grating has a front-end diffraction grating period and a front-end diffraction grating duty cycle; and a first back-end diffraction grating is formed in the lower semiconductor layer of the rear end portion of the distributed feedback laser Or the upper semiconductor layer, wherein the first back-end diffraction grating has a first back-end diffraction grating length, wherein the first back-end diffraction grating has a first back-end diffraction grating period a first back-end diffraction grating duty cycle; wherein the front-end diffraction grating length is greater than or equal to the first back-end diffraction grating length, wherein the front-end diffraction grating period is equal to the first back-end diffraction grating period Wherein the front-end diffraction grating duty cycle is greater than or equal to 40% and less than or equal to 60%, wherein the first back-end diffraction grating duty cycle (1) is greater than 0% and less than 40%, or (2) is greater than 60% and less than 100%. The modified laser diode modified structure according to claim 1, wherein the front end diffraction One distance between the grating and the active layer is equal to a distance between the first back-end diffraction grating and the active layer. The modified laser diode modified structure according to claim 2, wherein (1) the front end diffraction grating is formed in the lower semiconductor layer of the front end portion of the distributed feedback laser, and The first back-end diffraction grating is formed in the upper semiconductor layer of the rear end portion of the distributed feedback laser, wherein the distributed feedback laser further includes a second back-end diffraction grating, wherein the first a second back diffraction grating is formed in the lower semiconductor layer of the rear end portion of the distributed feedback laser, or (2) the front end diffraction grating is formed at the front end portion of the distributed feedback laser In the upper semiconductor layer, the first back-end diffraction grating is formed in the lower semiconductor layer of the rear end portion of the distributed feedback laser, wherein the distributed feedback laser further includes a second back end a diffraction grating, wherein the second back diffraction grating is formed in the upper semiconductor layer of the rear end portion of the distributed feedback laser; wherein the second rear diffraction grating is between the active layer and the active layer a distance equal to the distance between the front end diffraction grating and the active layer, wherein The second back-end diffraction grating has a second back-end diffraction grating length, wherein the second back-end diffraction grating has a second back-end diffraction grating period and a second back-end diffraction grating duty cycle. The length of the second back-end diffraction grating is equal to the length of the first back-end diffraction grating, wherein the front-end diffraction grating period is equal to the second back-end diffraction grating period, wherein the second back-end diffraction grating The liability cycle is equal to 100%. The modified laser diode modified structure of claim 1, wherein a distance between the front end diffraction grating and the active layer is smaller than the first rear diffraction grating and the active layer. One of the distances. The modified laser diode modified structure according to claim 4, wherein (1) the front end diffraction grating is formed in the upper semiconductor layer of the front end portion of the distributed feedback laser, and The first back-end diffraction grating is formed in the upper semiconductor layer of the rear end portion of the distributed feedback laser, wherein the distributed feedback laser further includes a second back-end diffraction grating, wherein the first a second back diffraction grating is formed in the upper semiconductor layer of the rear end portion of the distributed feedback laser, and the second rear diffraction grating is located at the first rear diffraction grating and the active layer (2) the front-end diffraction grating is formed in the upper semiconductor layer of the front end portion of the distributed feedback laser, and the first rear-end diffraction grating is formed in the distributed feedback laser In the lower semiconductor layer of the rear end portion, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed after the distributed feedback laser (3) the front end diffraction grating is formed in the lower semiconductor layer of the front end portion of the distributed feedback laser, and the first rear diffraction grating system is formed in the upper semiconductor layer Distributing feedback in the lower semiconductor layer of the back end portion of the laser, wherein the distributed feedback The shot further includes a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the lower semiconductor layer of the rear end portion of the distributed feedback laser, and the second rear end is diffracted a grating is located between the first back-end diffraction grating and the active layer; or (4) the front-end diffraction grating is formed in the lower semiconductor layer of the front end portion of the distributed feedback laser, and the a back-end diffraction grating is formed in the upper semiconductor layer of the rear end portion of the distributed feedback laser, wherein the distributed feedback laser further includes a second back-end diffraction grating, wherein the second rear An end diffraction grating is formed in the lower semiconductor layer of the rear end portion of the distributed feedback laser; wherein a distance between the second back diffraction grating and the active layer is equal to the front end diffraction grating The distance from the active layer, wherein the second back-end diffraction grating has a second back-end diffraction grating length, wherein the second back-end diffraction grating has a second back-end diffraction grating period and a second back end diffraction grating duty cycle, wherein the second back end diffraction grating The rear end of the first line is equal to the length of the diffraction grating, wherein the diffraction grating period of the distal end of the line is equal to The second back-end diffraction grating period, wherein the second back-end diffraction grating duty cycle is equal to 100%. The modified laser diode modified structure of claim 1, wherein the lower semiconductor layer is an n-type semiconductor layer. The modified laser diode modified structure of claim 1, wherein the upper semiconductor layer is a p-type semiconductor layer. The modified laser diode modified structure according to claim 1, wherein the modulated laser diode system is a direct modulation laser diode. The modified laser diode modified structure of claim 1, further comprising an electro-optic absorption modulator, wherein the electro-optic absorption modulator is formed on the semiconductor substrate, Wherein the front end portion of the distributed feedback laser is located between the rear end portion of the distributed feedback laser and the electro-optic absorption modulator, wherein the modulated laser diode system is an electro-optic light Absorbs the modulated laser diode. The modified laser diode modified structure according to any one of claims 1 to 9, wherein a ratio of a length of the front end diffraction grating to a length of the first rear diffraction grating is greater than or Equal to 1, and less than or equal to 4. The modulated laser diode improved structure according to any one of the preceding claims, wherein the first back-end diffraction grating duty cycle (1) is greater than 0% and less than or equal to 25%, or (2) greater than or equal to 75% and less than 100%. The modified laser diode modified structure of claim 11, wherein the ratio of the length of the front end diffraction grating to the length of the first rear diffraction grating is greater than or equal to 1, and less than or equal to 4 . A modified laser diode improved structure, comprising: a semiconductor substrate; and a distributed feedback laser formed on the semiconductor substrate, wherein the distributed feedback laser is divided into a front end portion and a rear end portion, wherein the distributed feedback laser comprises: a lower semiconductor a layer is formed on the semiconductor substrate; an active layer is formed on the lower semiconductor layer; an upper semiconductor layer is formed on the active layer; and a front end diffraction grating is formed in the distribution Retrieving the lower semiconductor layer of the front end portion of the laser or the upper semiconductor layer, wherein the front end diffraction grating has a front end diffraction grating length, wherein the front end diffraction grating has a front end diffraction grating period and a a front end diffraction grating duty cycle; and a first back end diffraction grating formed in the lower semiconductor layer or the upper semiconductor layer of the rear end portion of the distributed feedback laser, wherein the first back end The diffraction grating has a first back-end diffraction grating length, wherein the first back-end diffraction grating has a first back-end diffraction grating period and a first back-end diffraction grating duty cycle; The length of the front-end diffraction grating is greater than or equal to the length of the first back-end diffraction grating, wherein the front-end diffraction grating period is equal to the first back-end diffraction grating period, wherein the front-end diffraction grating duty period is greater than or equal to 40% and less than or equal to 60%, wherein a distance between the front end diffraction grating and the active layer is less than a distance between the first rear end diffraction grating and the active layer. The modulated laser diode modified structure of claim 13, wherein the first back-end diffraction grating duty cycle is greater than or equal to 40% and less than or equal to 60%. The modified laser diode improved structure according to claim 14 of the patent application, wherein (1) a front end diffraction grating is formed in the upper semiconductor layer of the front end portion of the distributed feedback laser, and the first rear end diffraction grating is formed on the rear end portion of the distributed feedback laser In the semiconductor layer, the distributed feedback laser further includes a second back-end diffraction grating, wherein the second back-end diffraction grating is formed on the upper semiconductor layer of the rear end portion of the distributed feedback laser And the second back-end diffraction grating is located between the first back-end diffraction grating and the active layer; (2) the front-end diffraction grating is formed at the front end of the distributed feedback laser In the upper semiconductor layer, the first back-end diffraction grating is formed in the lower semiconductor layer of the rear end portion of the distributed feedback laser, wherein the distributed feedback laser further includes a second back end a diffraction grating, wherein the second rear diffraction grating is formed in the upper semiconductor layer of the rear end portion of the distributed feedback laser; (3) the front diffraction grating system is formed on the distributed feedback lightning Shooting in the lower semiconductor layer of the front end portion, and the first back end diffraction grating system Forming in the lower semiconductor layer of the rear end portion of the distributed feedback laser, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed on The distributed back-feeding laser is disposed in the lower semiconductor layer of the rear end portion, and the second rear-end diffraction grating is located between the first back-end diffraction grating and the active layer; or (4) the front end a diffraction grating is formed in the lower semiconductor layer of the front end portion of the distributed feedback laser, and the first rear diffraction grating is formed on the upper semiconductor of the rear end portion of the distributed feedback laser The layer, wherein the distributed feedback laser further comprises a second back-end diffraction grating, wherein the second back-end diffraction grating is formed in the lower semiconductor layer of the rear end portion of the distributed feedback laser Wherein the distance between the second back-end diffraction grating and the active layer is equal to the distance between the front-end diffraction grating and the active layer, wherein the second back-end diffraction grating has a second End diffraction grating length, wherein the second rear diffraction grating has a second back end And a second grating period exit diffraction grating responsibility rear end of the task period, wherein the rear end of the second diffraction grating length The degree is equal to the length of the first back-end diffraction grating, wherein the front-end diffraction grating period is equal to the second back-end diffraction grating period, wherein the second back-end diffraction grating duty cycle is equal to 100%. The modified laser diode modified structure of claim 13, wherein the lower semiconductor layer is an n-type semiconductor layer. The modified laser diode modified structure of claim 13, wherein the upper semiconductor layer is a p-type semiconductor layer. The modified laser diode improved structure according to claim 13, wherein the modulated laser diode system is a direct modulation laser diode. The modified laser diode modified structure of claim 13, further comprising an electro-optic absorption modulator, wherein the electro-optic absorption modulator is formed on the semiconductor substrate, Wherein the front end portion of the distributed feedback laser is located between the rear end portion of the distributed feedback laser and the electro-optic absorption modulator, wherein the modulated laser diode system is an electro-optic light Absorbs the modulated laser diode. The modified laser diode modified structure according to any one of claims 13 to 19, wherein a ratio of a length of the front end diffraction grating to a length of the first rear diffraction grating is greater than or Equal to 1, and less than or equal to 4.