CN104166195A - Wavelength division multiplexing filtering optical receiver - Google Patents

Abstract

The invention provides a wavelength division multiplexing filter optical receiver, which includes an incident optical fiber, and an optical detection chip is arranged at one end opposite to the incident optical fiber, wherein a diverging lens, a filter and a focusing lens are sequentially arranged between the incident optical fiber and the optical detection chip. The lens, the light beams of different wavelengths emitted from the incident optical fiber pass through the diverging lens and then enter the filter in parallel, and the light beams passing through the filter are focused onto the light detection chip. The wavelength division multiplexing filter optical receiver provided by the invention filters light beams of different wavelengths at the light receiving end, and has a wide application range.

Description

WDM filter optical receiver

technical field

The invention relates to an optical device used in an optical fiber communication system, in particular to a wavelength division multiplexing filter optical receiver.

Background technique

The current optical receiving device (Receiver Optical Subassembly, ROSA) is usually used to receive the beam transmitted by the optical fiber and detect the beam. Some existing light receiving devices have a light detection chip for receiving and detecting the light beam output by the optical fiber. However, the existing optical receiving devices usually can only receive and detect one optical signal, which results in a limited bandwidth of the optical receiving device.

Therefore, people consider using wavelength division multiplexing technology to filter the beam transmitted by an optical fiber, using multiple filters to filter and split beams of different wavelengths, and to detect the filtered beams respectively. As shown in Figure 1, the existing light-receiving device receives the light beam emitted by the incident optical fiber 10, and the light-receiving device has an incident collimating lens 11, an internal reflector 13 and four filters 16, 17, 18, 19, and is also provided with Four outgoing collimating lenses 21 , 22 , 23 , 24 and four light detection chips 26 , 27 , 28 , 29 .

The light beams emitted by the incident fiber 10 are light beams with four wavelengths, such as light beams with wavelengths λ1, λ2, λ3, and λ4. The incident collimating lens 11 receives the light beam emitted by the incident optical fiber 10 and collimates the light beam. The light beam enters the incident collimating lens 11 and forms a light column, which is countless parallel beams. In addition, the incident collimating lens 11 does not filter the light beams, so each outgoing light beam includes light beams with wavelengths λ1, λ2, λ3, and λ4.

The outer side of the incident collimating lens 11 is provided with an internal reflector 13, and the internal reflector 13 includes a pair of opposite end surfaces, which are respectively a first end surface 14 close to the light incident collimating lens 11 and a second end surface opposite to the first end surface 14. The end faces 15 , the first end face 14 and the second end face 15 are arranged in parallel. Moreover, the first end surface 14 forms an acute angle with the axis of the incident collimating lens 11 . A part of the first end face 14 of the inner reflector 13 is coated with a reflective film, and another part is coated with an anti-reflection film. The second end face 15 is provided with four filters 16 , 17 , 18 , 19 .

After the light beam is incident on the area coated with the anti-reflection film on the first end face 14 of the internal reflector 13, it is incident on the first filter 16 on the second end face 15, and the filter 16 filters the light beam with a wavelength of λ1, that is, the wavelength The light beam of λ1 can pass through the filter 16 , and the light beams of other wavelengths are reflected to the area where the first end surface 14 of the internal reflector 13 is coated with a reflective film.

As shown in Figure 2, the light beam L13 is incident on the internal reflector 13 to form a light beam L14, the light beam with a wavelength of λ1 passes through the filter 16 to form a light beam L15, and the light beams with other wavelengths are L16 and are reflected by the filter 16 to the internal reflector 13 On the first end face 14 of the Since the first end surface 14 of the internal reflector 13 is coated with a reflective film, the light beam L16 is reflected on the first end surface 14 to form a light beam L17. When the light beam L17 is incident on the second filter 17, the light beam L18 with a wavelength of λ2 passes The light beams of other wavelengths, ie, the light beams L19 with wavelengths λ3 and λ4 are reflected to the first end surface 14 of the internal reflector 13 by the filter plate 17 .

The light beam L19 is reflected by the first end face 14 of the internal reflector 13 to form a light beam L20 and is incident on the third filter 18, the light beam L21 with a wavelength of λ3 passes through the filter 18, and the light beam L22 with a wavelength of λ4 is reflected by the filter 18 Back on the first end face 14. The light beam L22 is reflected on the first end face 14 to form a light beam L23, and the light beam L23 with a wavelength of λ4 passes through the filter 19 to form a light beam L24. Therefore, the light beams L15, L18, L21, L24 emerging from the filters 16, 17, 18, 19 are light beams with wavelengths λ1, λ2, λ3, λ4, respectively.

The outside of filter sheet 16,17,18,19 is provided with four outgoing collimating lenses 21,22,23,24, and four outgoing collimating lenses 21,22,23,24 are respectively connected with four filtering sheets 16,17, 18 and 19 correspond one-to-one, and the light beams L15 , L18 , L21 , and L24 emitted from the filters 16 , 17 , 18 , and 19 are respectively incident on the outgoing collimating lenses 21 , 22 , 23 , and 24 .

It can be seen from Fig. 1 that the light beams passing through each filter 16, 17, 18, 19 are parallel light beams, and the parallel light beams passing through the same filter are synthesized and converged correspondingly on the outgoing collimating lenses 21, 22, 23, 24 beam.

A light detection chip 26, 27, 28, 29 is arranged outside each outgoing collimating lens 21, 22, 23, 24, and each light detecting chip 26, 27, 28, 29 receives the outgoing collimating lens 21 correspondingly. , 22, 23, 24 outgoing light beams, and detect the received light beams. And, four light detecting chips 26, 27, 28, 29 are positioned at the outsides of the outgoing collimating lenses 21, 22, 23, 24, and the four light detecting chips 26, 27, 28, 29 are all positioned on the same side of the internal reflector 13. side outside.

Existing light-receiving devices filter light beams of different wavelengths separately, and receive and detect light beams of different wavelengths respectively, so it is necessary to use an internal reflector with a reflective film and a large number of filters. However, this light receiving device actually filters the light beams of different wavelengths at the light source end. At the light receiving end, that is, on the side of the light detection chip, the light beams are not filtered. The light beams pass through the collimator and directly enter the light detection on chip.

Since a large number of filters are required to filter the light beam at the light source end, if only the light beam with a specific wavelength needs to be detected at the light receiving end, the detection cost of the light beam is often high, and the application of the light receiving device is also limited.

Contents of the invention

The main object of the present invention is to provide a wavelength division multiplexing filter optical receiver for filtering light beams at the optical receiving end.

Another object of the present invention is to provide a wavelength division multiplexing filter optical receiver with low cost for beam detection.

In order to achieve the above-mentioned main purpose, the multi-channel optical receiving device provided by the present invention includes an incident optical fiber, and an optical detection chip is arranged at one end opposite to the incident optical fiber, wherein a diverging lens and a filter are arranged in sequence between the incident optical fiber and the optical detection chip As well as a focusing lens, light beams of different wavelengths emitted from the incident optical fiber pass through the diverging lens and then enter the filter in parallel, and the light beams passing through the filter are focused onto the light detection chip.

It can be seen from the above scheme that the beams of different wavelengths emitted from the incident fiber pass through the diverging lens to form multiple parallel beams. After the beams of different wavelengths are incident on the filter, the beam of a specific wavelength passes through the filter and enters after passing through the focusing lens. to the light detector. In this way, a filter is provided at the light receiving end to filter a specific wavelength, thereby obtaining a light beam of a specific wavelength, without wavelength selection at the light source end, and expanding the use range of the optical receiver.

A preferred solution is that the diverging lens, the filter and the focusing lens are packaged in the packaging column, and the diverging lens and the focusing lens are arranged opposite to each other and respectively fixed at both ends of the packaging column.

It can be seen that packaging the diverging lens, the filter and the focusing lens together through the packaging column is beneficial to reducing the volume of the optical receiver, simplifying the component process of the optical receiver, and reducing the production cost of the optical receiver.

A further solution is that the light detection chip is packaged on the base, and the base is provided with a packaging cap at one end facing the packaging column, and the light detection chip is located in a cavity surrounded by the base and the packaging cap.

It can be seen that the photodetection chip is packaged in the cavity surrounded by the packaging cap and the base, and the photodetection chip is protected by the packaging cap, which is beneficial to prolong the service life of the photodetection chip.

A further solution is that an installation seat is provided outside the packaging column and the packaging cap, and the packaging column and the packaging cap are fixed in the installation seat.

It can be seen that the mounting base is used to fix the package post and the package cap, so that the connection between the package post and the package cap is more reliable, and the volume of the optical receiver is also reduced.

Description of drawings

FIG. 1 is a schematic structural diagram of a conventional multi-channel light receiving device.

Fig. 2 is an optical path diagram of an optical path of a conventional multi-channel light receiving device.

Fig. 3 is a structural diagram of an embodiment of the present invention.

Fig. 4 is a reduced structure exploded view of the embodiment of the present invention.

Fig. 5 is a cross-sectional view of an embodiment of the present invention.

Fig. 6 is an exploded and enlarged view of the structure of the adapter and the optical fiber in the embodiment of the present invention.

Fig. 7 is an exploded and enlarged view of the structure of the diverging lens, the filter, the focusing lens and the packaging column in the embodiment of the present invention.

Fig. 8 is an enlarged view of the structure of the photodetector in the embodiment of the present invention.

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Detailed ways

The wavelength division multiplexing filtering optical receiver of the present invention can receive light beams of different wavelengths, filter the light beams of specific wavelengths in the light beams, and receive and detect the light beams of specific wavelengths. The wavelength division multiplexing filtering optical receiver of the present invention is applied in a dense wavelength division multiplexing optical transmission system with wide bandwidth.

Referring to FIG. 3 and FIG. 4 , the light receiving device of this embodiment has an adapter 30 , an incident optical fiber is installed in the adapter 30 , a photodetector 50 is provided at the opposite end of the incident optical fiber 30 , and a photodetection chip is arranged in the photodetector 50 . Between the adapter 30 and the photodetector 50 are a connecting piece 35 and a mounting base 46 , the connecting piece 35 is located between the adapter 30 and the mounting base 46 , and the packaging column 40 is installed in the mounting base 46 .

Referring to Fig. 5, the adapter 30 is positioned at one end of the wavelength division multiplexing filtering optical receiver, and the photodetector 50 is positioned at the other end of the wavelength division multiplexing filtering optical receiver. The optical fiber 33 exits and goes to the side close to the photodetector 50 .

Referring to FIG. 6 , a connector 31 is provided at the end of the adapter 30 away from the photodetector 50 for connecting with the optical fiber of the optical fiber communication system, so as to realize the connection between the WDM filter optical receiver and the external optical fiber. The incident optical fiber 33 is installed in the adapter 30. In order to realize the fixed installation of the incident optical fiber 33, a ceramic ring 32 is arranged in the adapter 30. As can be seen from FIG. The cross section is "C" type. The incident optical fiber 33 is fixedly installed in the ceramic ring 32, so that the optical fiber 33 is fixed.

It can be seen from FIG. 5 that the ceramic ring 32 is fixed in the connector 31 and the adapter 30 , and one end of the connector 31 is fixed in the adapter 30 . One end of the incident fiber 33 is installed in the ceramic ring 32 , and one end of the incident fiber 33 close to the mounting seat 46 is located outside the ceramic ring 32 and inside the adapter 30 . A connecting piece 35 is sheathed on an end of the adapter 30 close to the mounting base 46 , the lower end surface of the connecting piece 35 is adjacent to the end surface of the mounting base 46 , and the connecting piece 35 is fixed on the mounting base 46 .

A diverging lens 41, a filter 43, and a focusing lens 44 are arranged between the incident optical fiber 33 and the photodetector 50. After the light beam emitted from the incident optical fiber 33 enters the diverging lens 41, multiple beams of parallel light beams are formed, that is, light beams of different wavelengths It exits from the diverging lens 41 in parallel and enters the filter 43 in parallel. In this way, light beams of different wavelengths are separated after passing through the diverging lens 41 , which is beneficial to filtering by the filter 43 . It can be seen that the adapter 30 is arranged outside the end of the diverging lens 41 close to the incident optical fiber 33 .

The filter 43 is a dense wavelength division multiplexing filter, which is used to filter the light beam of a specific wavelength, that is, the light beam of a specific wavelength can pass through the filter 43 and emerge from the filter 43, but the light beams of other wavelengths cannot pass through the filter, so that Isolate light beams other than specific wavelengths. After the light beam passing through the filter 43 is incident on the focusing lens 44, it is focused by the focusing lens 44 onto the light detection chip 52 of the photodetector 50, and the light detection chip 52 receives and detects the incident light beam.

Referring to FIG. 7 , the diverging lens 41 , the filter 43 and the focusing lens 44 are fixedly installed in the packaging column 40 , and the diverging lens 41 and the focusing lens 44 are oppositely located at both ends of the packaging column 40 . The diverging lens 41 is hemispherical, and has a hemispherical surface 42 and a plane opposite to the hemispherical surface. The hemispherical surface 42 is set toward the incident fiber 33, which is beneficial to disperse the beam emitted by the incident fiber 33 into a parallel beam.

The focusing lens 44 is also hemispherical, and has a hemispherical surface 45 and a flat surface disposed opposite to the hemispherical surface 45 , and the hemispherical surface 45 is disposed facing the photodetector 50 . The filter 43 is located between the diverging lens 41 and the focusing lens 44 , and the plane of the diverging lens 41 faces the filter 43 , and the plane of the focusing lens 44 also faces the filter 43 . Preferably, the axis of the diverging lens 41 and the axis of the focusing lens 44 are on the same straight line, and the straight line passes through the filter 43 . Moreover, the cross section of the filter 43 is smaller than the area of the plane of the diverging lens 41 and also smaller than the area of the plane of the focusing lens 44 .

In order to facilitate the manufacture of the wavelength division multiplexing filter optical receiver, the diverging lens 41 and the focusing lens 44 are lenses of shape and size, that is, the same hemispherical lens can be used as the diverging lens 41 and the focusing lens 44 again.

In this embodiment, the diverging lens 41, the filter 43 and the focusing lens 44 are packaged in the packaging column 40, which can ensure that the positions of the diverging lens 41, the filter 43 and the focusing lens 44 are fixed, and the wavelength division multiplexing filter optical receiver is assembled. When , fewer devices need to be assembled, which is beneficial to the assembly and production of wavelength division multiplexing filter optical receivers.

Referring to FIG. 8 , the photodetector 50 has a base 51 , and a plurality of pins 54 are provided at the lower end of the base 51 , and the photodetector 50 receives electric power through the plurality of pins 54 . The light detection chip 52 is packaged on the base 51 , and the base 51 is provided with a package cap 53 , and the package cap 53 is located on a side of the base 52 close to the package column 40 . In this way, the light detection chip 52 is packaged in the cavity surrounded by the base 51 and the packaging cap 53 , so as to protect the light detection chip 52 .

Mounting base 46 is sheathed on packaging column 40 and packaging cap 53. As can be seen from FIG. The fixed connection of the packaging post 40 and the packaging cap 53 also fixes the positions of the diverging lens 41 , the filter 43 , the focusing lens 44 , and the photodetection chip 52 .

Since the filter 43 is set in the wavelength division multiplexing filter optical receiver, the light beam of a specific wavelength can be filtered at the light receiving end, the light beam of a specific wavelength can be obtained, and the light beams of other wavelengths can be isolated to expand the use of light receiving devices scope. In addition, a diverging lens 41 and a focusing lens 44 are arranged at both ends of the filter 43 to separate the light beam emitted from the incident optical fiber 33 to form parallel light beams, and then filter the light beams to ensure the stability of the filtering. In addition, the light beam passing through the filter 43 is focused onto the light detection chip 52 by the focusing lens 44 , so as to improve the stability of the light beam incident on the light detection chip 52 .

Certainly, the above-mentioned solution is only the preferred above-mentioned method of the present invention, and more changes can be made during practical application. For example, the diverging lens, the filter and the focusing lens can be packaged separately, not necessarily in the packaging column; or, the diverging lens 1. The focusing lens is not a hemispherical lens, but an elliptical or other shaped lens, etc. These changes can all achieve the purpose of the present invention.

Finally, it should be emphasized that the present invention is not limited to the above-mentioned embodiments, such as changes in the shape of the photodetector, changes in the position of the photodetector chip mounted on the base, changes in the shape of the filter, etc. should also be included in the claims of the present invention. within the scope of protection.

Claims (10)

1. wavelength-division multiplex filtering optical receiver, comprises

Incident optical, one end relative with described incident optical is provided with photodetection chip;

It is characterized in that:

Between described incident optical and described photodetection chip, be provided with successively divergent lens, filter plate and condenser lens, after described divergent lens, incide abreast described filter plate from the different wave length light beam of described incident optical outgoing, focus on described photodetection chip through the light beam of described filter plate.

2. wavelength-division multiplex filtering optical receiver according to claim 1, is characterized in that:

Described filter plate is dense wave division multipurpose filter plate.

3. wavelength-division multiplex filtering optical receiver according to claim 1 and 2, is characterized in that:

Described divergent lens, described filtering and described condenser lens are encapsulated in encapsulation post, and described divergent lens and described condenser lens are oppositely arranged and are separately fixed at the two ends of described encapsulation post.

4. wavelength-division multiplex filtering optical receiver according to claim 3, is characterized in that:

Described divergent lens is hemispherical, and the hemisphere face of described divergent lens is towards described incident optical setting.

5. wavelength-division multiplex filtering optical receiver according to claim 3, is characterized in that:

Described condenser lens is hemispherical, and the hemisphere face of described condenser lens arranges towards described photodetection chip.

6. wavelength-division multiplex filtering optical receiver according to claim 3, is characterized in that:

Described photodetection chip package is on pedestal.

7. wavelength-division multiplex filtering optical receiver according to claim 6, is characterized in that:

On described pedestal, be provided with encapsulation caps towards one end of described encapsulation post, described photodetection chip is positioned at the cavity that described pedestal and described encapsulation caps surround.

8. wavelength-division multiplex filtering optical receiver according to claim 6, is characterized in that:

Described encapsulation post and described encapsulation caps are provided with mount pad outward, and described encapsulation post and described encapsulation caps are fixed in described mount pad.

9. wavelength-division multiplex filtering optical receiver according to claim 1 and 2, is characterized in that:

Described incident optical is contained in adapter, and described adapter is arranged on the outside of described divergent lens near described incident optical one end.

10. wavelength-division multiplex filtering optical receiver according to claim 9, is characterized in that:

In described adapter, be provided with ceramic ring, described incident optical is fixed in described ceramic ring.