JP2005108880A - Resonator type surface emitting device, optical transmitter and optical transceiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resonator type surface light emitting device capable of preventing oxidation in a short wavelength region with small transmission loss in POF and improving the life in a high temperature and high humidity environment, and having no wafer warpage, and the same An object is to provide an optical transmitter or an optical transceiver used.

A first conductivity type in which a substrate 1 and a plurality of layers made of Al _z Ga _1-z As (0 ≦ z ≦ 1) and having different composition ratios are alternately stacked are formed on the substrate. A light reflecting layer 3; a light emitting layer 5 formed on the first conductive type light reflecting layer; and an In _y (Ga _1-x Al _x ) _1-y P (0 ≦ 0) formed on the light emitting layer. x ≦ 1, 0 ≦ y ≦ 1), and a second conductive type light reflecting layer 7 in which a plurality of layers having different composition ratios are alternately stacked, and the second conductive type light reflecting layer 7 provides a resonator-type surface light emitting element having a light reflectance lower than that of the first-conductivity-type light reflecting layer 3, and an optical transmitter or an optical transceiver using the same.

[Selection] Figure 1

Description

  The present invention relates to a resonator-type surface light-emitting device and an optical transmitter or an optical transceiver having the resonator-type surface light-emitting device, and more particularly to a resonator-type surface light-emitting device and an optical transmitter related to short-distance optical communication.

  In recent years, light-emitting diodes (LEDs) and semiconductor lasers (LDs) using III-V compound semiconductors have been widely used for optical communications, and support the socialization of IT.

  Generally speaking, optical communication refers to long-distance and large-capacity optical communication in the infrared region using a silica-based optical fiber. In recent years, short-distance optical communication of about 10 to 100 m in the visible region has also received the spotlight. This is due to the fact that optical transmission in the visible region has become possible due to the development of polymer-based optical fibers (POF). At present, short-distance optical communication at a transmission rate of 500 Mbps to 1 Gbps is being demonstrated using LEDs, and in the future, the LD is used to develop a transmission rate of 10 Gbps.

  Development of short-distance optical communication at a transmission speed of 500 Mbps to 1 Gbps is performed using a resonator-type surface light emitting element. Examples of the resonator type surface light emitting element include a resonator type light emitting diode (RC-LED) and a vertical cavity surface emitting laser (VCSEL) that can be said to be an advanced type thereof. . From the viewpoint of response speed, a laser is superior, but since it is expensive and has poor temperature characteristics, it is desirable to use a light emitting diode for short-distance optical communication. The RC-LED is a light emitting diode, but has high speed response and high directivity of emitted light, and is very suitable as an optical transmission light source.

FIG. 4 shows a sectional view of the structure of a conventional RC-LED. The emission wavelength is about 660 nm. A conventional RC-LED includes an n-type GaAs buffer layer 42, an n-type light reflecting layer 43, an n-type InGaAlP cladding layer 44, an InGaAlP-based MQW active layer 45, a p-type InGaAlP cladding layer 46, on an n-type GaAs substrate 41. A p-type light reflection layer 47 and a p-type InGaP moisture resistant layer 48 are sequentially stacked. Further, protons are selectively injected into a region excluding the central portion of the active layer that becomes a light emitting region, thereby forming a high resistance region 49. On the p-type InGaP moisture-resistant layer 48, a p-side electrode 50 having an opening just above the light emitting region is provided, and an n-side electrode 51 is provided on the back surface of the GaAs substrate 41. The n-type light reflecting layer 43 is composed of a DBR film (Distributed Bragg Reflector film) which is an alternate laminated film of a high refractive index film and a low refractive index film. The low refractive index film is Al _0.98 Ga _0.02 As, and the high refractive index film is Al _0.5 Ga _0.5 As, and lamination is started for 30.5 periods from the high refractive index film. . The p-type light reflection layer 47 is laminated for 10 periods using the same laminated film as the n-type light reflection layer.

In the conventional RC-LED having the above structure, the light generated in the light emitting region resonates between the upper and lower light reflecting layers, passes through the upper light reflecting layer, and is extracted from the light extraction surface on the upper surface of the element. In order to perform such surface light emission, the light reflecting layer is set to have different light reflectivities in the upper and lower sides. For example, the n-type light reflection layer 43 has a light reflectance of about 99%, and the p-side light reflection layer 47 has a light reflectance of about 90%. The light reflectance is set by changing the period of the alternately laminated film of the light reflecting layers up and down. In addition, the composition of Al _x Ga _1-x As is determined so that the upper and lower light reflecting layers do not absorb light with respect to the emission wavelength. Since Al _x Ga _1-x As used in the light reflecting layer is almost perfectly lattice matched with the substrate made of GaAs in the range of all Al compositions x, the greatest advantage is that there is no deterioration of crystallinity due to lattice distortion. (For example, refer to Patent Document 1).
JP 2002-111054 (7th page, FIG. 1)

  The resonator-type surface light emitting element used for short-distance optical communication is used as a key part of consumer equipment that is indispensable for low cost, so the usage environment is very severe. That is, since it is an inexpensive device that cannot have an expensive accessory such as a cooling mechanism, it must withstand a high temperature and high humidity environment.

  When making an RC-LED having a wavelength of 650 nm to 670 nm used for short-range communication, the light reflecting layer needs to be transparent to light from the light emitting region, and thus the Al composition must be increased. However, a light reflecting layer made of AlGaAs having a high Al composition like a conventional RC-LED is easily oxidized naturally, and therefore, the influence of oxidation is significant in a high temperature and high humidity environment. In particular, the oxidation of the upper p-side light reflection layer 47 is more remarkable than that of the lower n-type light reflection layer 43, and the portion of the p-type light reflection layer 47 directly below the p-side electrode 50 is a current injection region. Therefore, it is very easy to oxidize. Such oxidation of the p-type light reflection layer 47 causes high resistance, devitrification, and performance degradation of the device, and a sufficient device life cannot be obtained. In the conventional RC-LED shown in FIG. 4, an InGaP moisture-resistant layer 48 that does not contain Al is provided between the light reflecting layer 47 and the element surface in order to prevent element deterioration due to moisture absorption from the light emitting side. Thereby, oxidation of the p-type light reflection layer 47 caused by moisture absorption is slightly prevented. However, the portion of the p-type light reflection layer 47 directly under the p-side electrode 50 is still easily oxidized and cannot be said to have sufficient oxidation resistance.

  As described above, in the conventional RC-LED, the oxidation of the p-type light reflection layer 47 is remarkable in a high temperature and high humidity environment, resulting in high resistance, devitrification, and performance deterioration, and a sufficient device life cannot be obtained. It was.

  When optical communication is performed using POF, it is preferable to use an element having a wavelength of about 650 nm in order to minimize POF transmission loss. However, the shorter the wavelength, the higher the Al composition must be in order to form a light reflecting layer that is transparent to the wavelength.

  Therefore, it becomes impossible to secure a difference in refractive index between the high refractive index film and the low refractive index film of the light reflecting layer, and the light reflectance of the light reflecting layer is lowered. In order to prevent the light reflectivity from decreasing, the stacking period may be increased. However, if the stacking period is excessively increased, there is a problem that the element resistance is increased and the light intensity is decreased.

  Furthermore, the AlGaAs n-type light reflecting layer 43 grown on the GaAs substrate 41 has a lattice constant larger than that of the GaAs substrate and has a larger layer thickness, and therefore has compressive strain on the substrate. This compressive strain causes a convex warpage or film cracking. The above problems can be commonly applied to not only RC-LEDs but also VCSELs.

  The present invention has been made on the basis of recognition of such a problem, and an object of the present invention is to prevent oxidation in a short wavelength region where transmission loss is small in POF, to improve the life in a high temperature and high humidity environment, and to provide a wafer. An object of the present invention is to provide a resonator-type surface light emitting device without warping. Another object of the present invention is to provide an optical transmitter or an optical transceiver formed by sealing such a resonator type surface light emitting element.

In order to achieve the above object, a resonator-type surface light emitting device according to the present invention includes a substrate and Al _z Ga _1-z As (0 ≦ z ≦ 1) formed on the substrate and having different composition ratios. A first conductive type light reflecting layer in which a plurality of layers are alternately stacked; a first conductive type cladding layer formed on the first conductive type light reflecting layer; and the first conductive type cladding layer. An active layer formed on the active layer, a second conductive type cladding layer formed on the active layer, and an in _y (Ga _1-x Al _x ) ₁₋ formed on the second conductive type cladding layer. a second reflection type light reflection layer comprising _y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) and a plurality of layers having different composition ratios alternately stacked, the second conductivity type The light reflecting layer has a light reflectance lower than that of the first conductive type light reflecting layer.

  The optical transmitter according to the present invention includes a first electrode formed on the second-conductivity-type light reflecting layer, and a second electrode formed on the surface opposite to the element formation surface of the substrate. 5. The resonator-type surface light emitting device according to claim 2, a first lead connected to the first electrode, and a second lead connected to the second electrode. A second lead; a drive circuit for driving the resonator-type surface light-emitting element; a part of the first lead and a part of the second lead; the resonator-type surface light-emitting element; and the drive circuit. And an envelope for sealing.

  The optical transceiver according to the present invention includes a first electrode formed on the light-reflecting layer of the second conductivity type, and a second electrode formed on the surface opposite to the element forming surface of the substrate. 5. The resonator-type surface light emitting device according to claim 2, a first lead connected to the first electrode, and a first lead connected to the second electrode. Two leads, a drive circuit for driving the resonator-type surface light-emitting element, a light-receiving element, a part of the first lead and a part of the second lead, the resonator-type surface light-emitting element, An envelope for sealing the drive circuit and the light receiving element is provided.

As described above in detail, according to the present invention, the light reflecting layer on the light extraction surface side is made of In _y (Ga _1-x Al _x ) _1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1). By using such a DBR layer, oxidation can be prevented in a short wavelength region where transmission loss in POF is small, the life in a high temperature and high humidity environment can be improved, and warpage of the wafer can be prevented. In addition, the light reflectance and the desired value can be set without reducing the light intensity, the device can be made thinner and the device resistance can be reduced, and the heat dissipation characteristics of the device can be improved. Can do.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing a main part structure of a resonator-type surface light emitting element, that is, an RC-LED according to Example 1 of the present invention. The RC-LED of Example 1 emits light with a peak wavelength of 665 nm. Example 1 is characterized in that the n-type light reflection layer 7 on the light extraction side is made of In _y (Ga _1-x Al _x ) _1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) material. Specifically, it is composed of a DBR having a plurality of periods, in which a stack of an In _s Al _1-s P (0 ≦ s ≦ 1) layer and an In _t Ga _1-t P (0 ≦ t ≦ 1) layer is a period. It is characterized by. The structure of this RC-LED is as follows.

A p-type GaAs buffer layer 2 is provided on a p-type GaAs substrate 1, and a p-type Al _0.5 Ga _0.5 As high-refractive index layer and a p-type Al _0.95 Ga _0.05 As low-refractive index are formed thereon. The p-type light reflection layer 3 is formed of a DBR film in which 40 layers of rate layers are alternately stacked in this order. The p-type light reflection layer 3 is doped with carbon at 5 × 10 ¹⁸ cm ⁻³ or more for p-type conversion, and has a light reflectivity of 99.5% or more. A p-type In _0.5 (Ga _0.3 Al _0.7 ) _0.5 P cladding layer 4 is provided on the p-type light reflection layer 3, and an MQW structure made of an InGaAlP system is formed on the cladding layer 4. An active layer 5 is provided, and an n-type In _0.5 (Ga _0.3 Al _0.7 ) _0.5 P cladding layer 6 is provided on the active layer 5. On the cladding layer 6, an n-type light reflecting layer 7 made of In _y (Ga _1-x Al _x ) _1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1), that is, n-type In _{0. It} has an n-type light reflection layer 7 composed of a DBR film in which ₅ Ga _0.5 P high refractive index layers and n-type In _0.5 Al _0.5 P low refractive index layers are alternately laminated for 8 periods. The reflectance of the n-type light reflection layer 7 is about 95%. An n-type GaAs contact layer 8 having a thickness of 200 mm is provided on the n-type light reflection layer 7. From the contact layer 8 to the upper part of the p-type light reflection layer 3, a portion excluding the central portion serving as a light emitting region is provided. The current confinement layer 8 is formed by proton injection. From the current confinement layer 8 to the contact layer 8, an n-electrode 10 having an opening just above the light emitting region is provided. A p-electrode 11 is provided on the back surface of the substrate 1. The thicknesses of the high-refractive index layer and the low-refractive index layer constituting the p-type light reflection layer 3 and the n-type light reflection layer 7 are determined to be about 1 / 4n of the emission peak wavelength (n is the refractive index). Has been. The size of the light emitting part is 50 μmΦ.

Each semiconductor layer of the RC-LED of Example 1 is formed by MOCVD (metal organic chemical vapor deposition). Regarding the raw materials of the elements constituting each semiconductor, the In raw material is trimethylindium (TMI), the Ga raw material is triethylgallium (TEGa), the Al raw material is trimethylaluminum (TMA), the arsenic raw material is arsine (As ₃ ), and the phosphorus raw material is Phosphine (PH ₃ ) and nitrogen raw material use dimethylhydrazine. Silane (SiH ₄ ) is used for n-type doping, and dimethylzinc (DMZ) and carbon tetrabromide (CBr4) are used for p-type.

  The RC-LED having the above structure emits light in the active layer 5 by current injection. This light resonates between the p-type light reflection layer 3 and the n-type light reflection layer 7, and then the n-type light reflection layer. 7 is emitted upward.

  The RC-LED of Example 1 showed about 1.2 mW with almost the same light output as the conventional device. In addition, the transmission operation experiment at 500 Mps was successful. Moreover, in the energization test in a high-temperature and high-humidity environment with a temperature of 60 ° C. and a humidity of 90%, the light output was reduced by about 0.3 dB at 1000 Hr, and the most severe specifications expected could be cleared. In addition, an element resistance of 10Ω and a capacitance of 2 pF, a small RC product that has not been achieved in the past, could be obtained.

The feature of the RC-LED of Example 1 is that the n-type light reflection layer 7 has phosphide In _y (Ga _1-x Al _x ) _1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1). It is using the DBR layer which consists of. In general, the upper n-type light reflection layer 7 is easily oxidized in a high temperature and high humidity environment. Therefore, oxidation resistance can be improved by using only the upper n-type light reflection layer 7 as a phosphide excellent in chemical stability. Further, the structure of the n-type light reflecting layer 7 is more specifically the low refractive index layer of In _s Al _1-s P (0 ≦ s ≦ 1) and the high refractive index of In _t Ga _1-t P (0 ≦ t ≦ 1). It is a DBR layer composed of a plurality of periods with a period of lamination with a refractive index layer. In this case, the proportion of the Al composition in the n-type light reflection layer 7 is less than half. Therefore, it is possible to prevent oxidation by reducing the proportion of the Al composition that is easily oxidized.

Furthermore, since the Al composition of the low refractive index layer can be set freely, a sufficient refractive index difference can be obtained between the two layers, and the light reflectance can be set to a desired value. On the other hand, in the conventional element, when the peak wavelength is as short as 665 nm, it is necessary to increase the Al composition of both refractive index layers in order to prevent light absorption. If the Al composition is increased, oxidation occurs. Further, there is no difference in refractive index between the high refractive index layer and the low refractive index layer, and the light reflectance cannot be set to a desired value. The structure of the first embodiment can solve all the problems of the conventional device. Another feature of the first embodiment is that the p-type light reflection layer 3 is designed to be p-type, and the n-type light reflection layer 7 made of InGaAlP is designed to be n-type. Since n-type InGaAlP has high carrier mobility and is easily doped with n-type impurities, it has a lower resistance than p-type InGaAlP. Therefore, the resistance reduction is realized by using the n-type light reflection layer 7 made of InGaAlP as the n-type. The p-type light reflection layer 3 made of AlGaAs has a feature that it is easy to dope carbon, which is a p-type impurity. Therefore, by making the p-type light reflection layer 3 p-type, the resistance of the p-type light reflection layer 3 is reduced by doping carbon at a high concentration. AlGaAs is In
Since it has a lower thermal resistance than GaAlP, it is preferable from the viewpoint of heat dissipation that the p-type light reflection layer 3 close to the mount surface is made of AlGaAs.

  As described above, the RC-LED of Example 1 can prevent oxidation and improve the lifetime in a high-temperature and high-humidity environment in a short wavelength region where transmission loss in POF is small.

  In the above embodiment, the lamination period of the high refractive index layer and the low refractive index layer is 8 periods. However, if the period is 6 periods or more and 14 periods or less, desired light intensity and light reflectance can be obtained. In addition, the n-type light reflecting layer 7 can be made thinner and the device resistance can be reduced. If it is less than 6 cycles, a desired light reflectance cannot be obtained, and the spectrum width is expanded. Moreover, when it becomes longer than 14 cycles, the light intensity falls. In addition, the structure, material, composition, and the like of the light-emitting element can be changed as appropriate without departing from the above effects.

  Next, a modification of the first embodiment of the present invention will be described. FIG. 2 is a cross-sectional view showing a modification of the first embodiment of the present invention. In the first embodiment, GaAs is used for the contact layer. However, this modification is characterized in that GaP having a thickness of 100 mm is used for the contact layer. In FIG. 2, since the structure other than the contact layer 12 is the same as that of the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

  As described in Example 1, GaP which is a phosphide has extremely high chemical stability and does not cause oxidation due to moisture. Therefore, the device life can be improved.

  Further, since GaP has a larger band gap than GaAs, it is almost completely transparent to the emission wavelength. Therefore, approximately 4% of light absorbed by the GaAs contact layer in the conventional device can be transmitted, and the light extraction efficiency can be improved. In addition, GaP has a smaller refractive index difference from air than GaAs. This also leads to an improvement in light extraction efficiency.

  Incidentally, it is not easy to form the contact layer 12 made of GaP on the layer lattice-matched to the GaAs substrate 1 due to the difference in lattice constant between GaAs and GaP. However, in this modification, the thickness of the GaP contact layer 12 is reduced to reduce pseudomorphic growth, that is, the GaP contact layer 12 is forcibly grown with the lattice constant of the GaAs substrate 1, thereby reducing the crystallinity. Can be prevented.

  In this modification, the thickness of the GaP contact layer is 100 mm, which is consistent with the maximum thickness that allows GaP to grow on the GaAs substrate 1 as a high-quality crystal. Therefore, if it has a thickness of 100 mm or less and a layer thickness that can contact the electrode, the same effect as described above can be obtained.

  As a material of the contact layer 12, GaAsP can be used. Since GaAsP has a composition close to that of GaP, it has high moisture resistance and can improve the life as in GaP. In addition, since As is included, there is an advantage that lattice matching with the substrate is easy. However, if the ratio of As in GaAsP is high, the moisture resistance is lowered, the transmittance is lowered, and the light extraction efficiency is lowered. Therefore, the composition ratio of As is preferably 10% or less.

  The resonator-type surface light emitting device of Example 2 is an RC-LED that oscillates at a peak wavelength of 650 nm. Compared with the first embodiment, the peak wavelength is further shortened to further reduce the optical transmission loss in the POF.

  FIG. 3 is a cross-sectional view showing an RC-LED according to Example 2 of the present invention. Example 2 is characterized in that the n-type light reflection layer 27 has tensile strain. Since other structures are substantially the same as those of the first embodiment, the same portions are denoted by the same reference numerals and description thereof is omitted.

In the RC-LED of Example 2, the composition of the p-type light reflection layer 23 is the same as that of Example 1, but the period of the high refractive index layer and the low refractive index layer is 50, and the light reflectance is 99. .5% or more. The active layer 5 is made of InGaAlP, but has a higher Al composition than that of Example 1 in order to set the peak wavelength to 650 nm. The n-type light reflection layer 27, which is a feature of the second embodiment, is made of In _y (Ga _1-x Al _x ) _1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1). In _0.47 Ga _0.53 P, and the low refractive index layer is In _0.49 Al _0.51 P. Like Example 1, it is 6 cycles or more and 14 cycles or less, and the light reflectance is about 95%. The n-type light reflection 27 has an In composition of the high-refractive index layer and the low-refractive index layer lower than an In composition of about 0.5 that is lattice-matched with the GaAs substrate 1 and has a thickness sufficient to form a strain. Thus, the overall tensile strain is 0.2% on average.

  In Example 2, since the n-type light reflection layer 27 has a tensile strain of 0.2%, the light absorption edge of the n-type light reflection layer 27 is shortened to less than 650 nm. Therefore, light absorption at a peak wavelength of 650 nm emitted from the active layer 5 can be prevented, and light extraction efficiency can be increased. Moreover, the compressive strain of the p-type light reflection layer 23 can be relieved by the tensile strain of the n-type light reflection layer 27, and the warpage and film cracking of the wafer can be prevented. In this embodiment, the tensile strain is about 0.2%, but the tensile strain amount can be appropriately designed to such an extent that the wafer is not warped or cracked. If the tensile strain is larger than 0.3%, a strain larger than the compressive strain of the p-type light reflecting layer 23 is generated and a concave warp is formed on the top or a crack is generated in the epitaxial film. It is preferably 3% or less, more preferably 0.1 or more and 0.2.

  In addition, the RC-LED of Example 2 has the same effect as that of Example 1. That is, in a short wavelength region where transmission loss in POF is small, the oxidation resistance in a high temperature and high humidity environment can be improved, and the lifetime of the element can be improved. Further, the warpage of the wafer can be prevented. Furthermore, the light reflectivity and the desired value can be set without reducing the light intensity, the device can be made thinner and the device resistance can be reduced, and the heat dissipation characteristics of the device can be improved. Can do.

  The effect of introducing tensile strain is also effective in the case of the element of Example 1, that is, the element having a peak wavelength of 665 nm. The inventors measured the optical output of the device having a peak wavelength of 665 nm when a tensile strain was applied and when no tensile strain was applied. As a result of a 1000 Hr energization test in a high-temperature and high-humidity environment at a temperature of 60 ° C. and a humidity of 90%, an element with tensile strain causes a 0.1 dB output drop, and an element without tensile strain has an output of 0.2 dB. Showed a decline. Thus, it can be seen that the optical output characteristics are better when the tensile strain is applied.

    The RC-LEDs of the first and second embodiments described above are not limited to the above structure, and the structure can be changed within a range that does not lose the above effect. Further, the modification of the first embodiment may be combined with the second embodiment.

As mentioned above, although Example 1 thru | or Example 2 described RC-LED, it is possible to use the above structures also about VCSEL which is a structure substantially the same as RC-LED. In the case of a VCSEL, the light emission size is as small as 10 μmΦ or less compared to the RC-LED, and the period of the light reflection layer is slightly different, but the other structures are almost the same. By adopting the structure as in the above embodiment, in the case of VCSEL, the oxidation resistance under a high temperature and high humidity environment can be improved and the lifetime of the element can be improved. Further, the warpage of the wafer can be prevented. Furthermore, the light reflectivity and the desired value can be set without reducing the light intensity, the device can be made thinner and the device resistance can be reduced, and the heat dissipation characteristics of the device can be improved. Can do.

  Further, using the resonator-type surface light-emitting element described above, a resonator-type surface light-emitting element, a drive circuit for driving the resonance-type light-emitting element, and leads connected to the electrodes of the resonance-type light-emitting element, respectively It is possible to form an optical transmitter having these and sealing them with an envelope made of resin. Alternatively, the light receiving element can also be sealed to form an optical transceiver that performs transmission and reception. These optical transmitters or optical transceivers can be provided with small size and low cost.

Sectional drawing of the resonator type surface emitting element by Example 1 of this invention. Sectional drawing of the modification of Example 1 of this invention. Sectional drawing of the resonator type surface emitting element of Example 2 of this invention. Sectional drawing of the conventional resonator type surface emitting element.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 GaAs substrate 2 GaAs buffer layer 3, 23 p-type AlGaAs light reflection layer 4 p-type InGaAlP clad layer 5 active layer 6 n-type InGaAlP clad layer 7, 27 n-type InGaAlP light reflection layer 8 GaAs contact layer 9 current confinement layer 10 n Electrode 11 P electrode 12 GaP contact layer

Claims (13)

A substrate,
A light-reflecting layer of a first conductivity type formed on the substrate and made of Al _z Ga _1-z As (0 ≦ z ≦ 1) and having a plurality of layers alternately laminated with different composition ratios;
A first conductivity type cladding layer formed on the light reflection layer of the first conductivity type;
An active layer formed on the first conductivity type cladding layer;
A second conductivity type cladding layer formed on the active layer;
A layer formed on the second conductivity type cladding layer and made of In _y (Ga _1-x Al _x ) _1-y P (0 ≦ x ≦ 1, 0 ≦ y ≦ 1) and having a different composition ratio. A second conductive type light reflecting layer in which a plurality of layers are alternately stacked,
The resonator-type surface light emitting device, wherein the second conductive type light reflecting layer has a lower light reflectance than the first conductive type light reflecting layer. The second-conductivity-type light reflecting layer has a cycle of a stack of an In _s Al _1-s P (0 ≦ s ≦ 1) layer and an In _t Ga _1-t P (0 ≦ t ≦ 1) layer, 2. The resonator-type surface light emitting device according to claim 1, wherein the resonator type surface light emitting device is a layer having a plurality of periods. 3. The resonator-type surface light emitting device according to claim 2, wherein the second-conductivity-type light reflecting layer has a tensile strain of 0.3% or less. 4. The resonator-type surface emitting element according to claim 2, further comprising a contact layer made of GaP or GaAsP formed on the second conductive type light reflecting layer. 5. The resonator-type surface light emitting device according to claim 2, wherein the substrate is made of GaAs. A buffer layer of a first conductivity type made of GaAs between the substrate and the light reflection layer of the first conductivity type;
The active layer according to any one of _{In u (Ga 1-v Al} v) 1-u P (0 ≦ u ≦ 1,0 ≦ v ≦ 1) that consists characterized by claims 2 to 4 Resonator type surface light emitting device. 5. The resonator type according to claim 2, wherein the first conductive type light reflecting layer is p-type, and the second conductive type light reflecting layer is n-type. Surface light emitting device. 5. The resonator-type surface light emitting device according to claim 2, wherein the second-conductivity-type light reflecting layer has a period of 6 cycles or more and 14 cycles or less. 5. The resonator-type surface light emitting device according to claim 2, wherein the first conductivity type light reflecting layer is doped with carbon. 6. 5. The resonator type surface light emitting device according to claim 2, wherein the resonator type surface light emitting diode is a resonator type light emitting diode. The resonator type surface emitting device according to any one of claims 2 to 4, which is a vertical cavity surface emitting laser. A first electrode formed on the second conductive type light reflecting layer;
A second electrode formed on the surface of the substrate opposite to the element formation surface;
The resonator-type surface light-emitting device according to any one of claims 2 to 4,
A first lead connected to the first electrode;
A second lead connected to the second electrode;
A drive circuit for driving the resonator-type surface light emitting element;
An envelope for sealing a part of the first lead and a part of the second lead, the resonator-type surface light emitting element, and the drive circuit;
An optical transmitter comprising: A first electrode formed on the second conductive type light reflecting layer;
A second electrode formed on the surface of the substrate opposite to the element formation surface;
The resonator-type surface light-emitting device according to any one of claims 2 to 4,
A first lead connected to the first electrode;
A second lead connected to the second electrode;
A drive circuit for driving the resonator-type surface light emitting element;
A light receiving element;
An envelope for sealing a part of the first lead and a part of the second lead, the resonator-type surface light emitting element, the drive circuit, and the light receiving element;
An optical transceiver comprising:

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