JPH055911A - Semiconductor wavelength transducer - Google Patents

Abstract

PURPOSE:To offer a semi-conductor wavelength transducer requiring no isolators. CONSTITUTION:A wide-band distributed reflector 11 whose reflection factor is very higher than that of a narrow-band distributed reflection mirror part 5 on the exit side is arranged on the incidence side of a bistable wavelength transducer 12, and the input light of TM polarization is used as incident signal light, and the narrow-band distributed reflection mirror part 5 on the exit side to which the output light of TE polarization orthogonal to the input light is emitted is tuned to convert the wavelength. Since the incident signal light and the output signal light are in polarization states orthogonal to each other, the semiconductor wavelength transducer is constituted as a unidirectional device, and any isolators are not required; and since the distributed reflector 11 on the incidence side has a constitution adapted to an optical integrated circuit, this transducer is suitably integrated on a semiconductor substrate 1 independently or together with another optical element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor wavelength conversion device using a bistable laser, which is small and has a wide operating wavelength range.

[0002]

2. Description of the Related Art FIG. 14 shows a structural sectional view of an example of a conventionally known bistable semiconductor wavelength conversion device. Here, 1 is an n-type substrate such as an n-InP substrate, 2 is an n-type semiconductor clad layer such as n-InP disposed on the substrate 1,
Reference numerals 3, 4 and 5 are distributed reflection type mirror portions arranged on the cladding layer 2 and having a Bragg reflection (DBR) type diffraction grating for selecting a saturable absorption region, a gain region and a converted light wavelength, respectively. The optical waveguide layers constituting these 3 to 5 can be composed of InGaAsP. A p-type semiconductor clad layer 6 such as p-InP is arranged on the regions 3 and 4 and the diffraction grating 5 to form a ridge type optical waveguide. The saturable absorption region electrode 7, the gain region electrode 8 and the distributed reflector tuning electrode 9 are arranged on the cladding layer 6 in correspondence with the positions of the regions 3 and 4 and the diffraction grating 5, respectively. To do. An electrode 10 is arranged on the opposite main surface of the substrate 1. The input light of wavelength λ ₁ from the optical isolator 100 is made to enter the region 3.

Here, from the gain region electrode 8 to the active region 4
By injecting current into the active region 4, the active region 4 has a gain for light, and the wavelength-converted output light λ _X is turned on and off by the input light λ ₁ . At the same time, the wavelength λ _X of the converted light is controlled by changing the refractive index of the distributed Bragg reflector mirror portion 5 by the injection current from the tuning electrode 9.

Now, the operation when a signal light having a wavelength of λ ₁ is incident is explained as follows (reference document: S. Yama).
koshi et al. , Postdeadline
papers of OFC'88, PD-10 (1
988)).

In the bistable wavelength conversion element having the saturable absorption region 3, when the loss of the absorption region 3 is modulated by the incident light, the output light is turned on / off according to the intensity of the incident signal light.
The characteristic which does is obtained. The wavelength of the output light is determined by the Bragg wavelength of the diffraction grating 5. Therefore, since the output wavelength can be changed by changing the refractive index of the diffraction grating 5 by the current injected from the electrode 9, the output signal light having a wavelength different from the wavelength of the incident signal light can be controlled and obtained. You can This is the operating principle of the wavelength conversion element shown in FIG.

To actually operate this device, 1.5 μ
Incident power of about 15μ in m band InGaAsP element
W or more is required, and a wavelength conversion band of about 4.5 nm or more has been obtained.

[0007]

Since the converted light by such a conventional wavelength conversion element is emitted in both directions, the optical isolator 100 is indispensable to prevent the returned light of the converted light from affecting the preceding stage. Become. Since the optical isolator is made of a non-reciprocal material, it cannot be incorporated in the optical IC. This is a fatal drawback when it is difficult to form an optical isolator on a semiconductor wafer when the wavelength conversion elements are integrated on the same wafer.

As described above, a large-scale frequency switch is required when the communication system is entirely composed of optical devices, but such a large-scale frequency switch cannot be realized by the combination of individual elements according to the prior art. However, realization by an optical integrated circuit is desired.

Therefore, an object of the present invention is to eliminate the need for an isolator by preventing the converted light of the conventional bistable wavelength conversion element from returning to the incident side, so that it can be used alone or with other elements on the same wafer. An object of the present invention is to provide a semiconductor wavelength conversion element that is appropriately configured for integration.

[0010]

In order to achieve such an object, the invention according to claim 1 provides a saturable absorption region, a gain region, and a semiconductor substrate on which a saturable absorption region and a gain region are provided. A distributed reflection type mirror portion configured to include a diffraction grating for selecting a converted light wavelength is arranged, and the saturable absorption region,
A first cladding layer, which corresponds to the saturable absorption region, the gain region, and the distributed Bragg reflector mirror unit, and is separated from each other, on the gain region and the distributed Bragg reflector unit via a second cladding layer. In the semiconductor wavelength conversion element in which the second and third electrodes are arranged, a diffraction grating having a coupling coefficient larger than that of the diffraction grating of the distributed reflection mirror section is provided on the light incident side of the saturable absorption region, A distributed reflector that transmits the incident signal light in one polarization state is disposed, and the converted light in the second polarization state orthogonal to the first polarization state is extracted from the distributed reflection mirror unit, and the converted light is obtained. Is controlled by the injection current from the third electrode.

According to a second aspect of the present invention, in the first aspect, the first polarization state is the TM polarization state, and the second polarization state is the second polarization state.
By setting the polarization state to the TE polarization state and setting the waveguide cross-sectional shape of the gain region to a short rectangle in the layer thickness direction, TE
The confinement coefficient of the polarized wave inside the gain region is made larger than the confinement coefficient of the TM polarized wave inside the gain region to enable the conversion light extraction of the TE polarization state.

According to a third aspect of the present invention, in the first aspect, the first polarization state is the TE polarization state, and the second polarization state is the TE polarization state.
The polarization state is changed to the TM polarization state, and the cross-sectional shape of the waveguide in the gain region is a rectangle long in the layer thickness direction.
The confinement coefficient of the polarized wave inside the gain region is made larger than the confinement coefficient of the TE polarized wave inside the gain region to enable conversion light extraction of the TM polarized state.

According to a fourth aspect of the present invention, in the first aspect, the first polarization state is the TM polarization state, and the second polarization state is the second polarization state.
The polarization state is set to the TE polarization state, and the distortion amount is 0 in the gain region.
By configuring the quantum well structure having the above-mentioned compressive strain, the material gain of the TE polarized light is made larger than the material gain of the TM polarized light to enable the conversion light extraction of the TE polarized state. ..

According to a fifth aspect of the present invention, in the second aspect, the first polarization state is the TE polarization state, and the second polarization state is the TE polarization state.
By setting the polarization state to the TM polarization state and configuring the gain region with a quantum well structure having extension strain, the material gain of the TM polarization is made larger than that of the TE polarization, and It is characterized in that converted light can be taken out.

According to a sixth aspect of the present invention, in the first aspect, the optical waveguide layer of the distributed reflector has a multiple quantum well structure.

The invention according to claim 7 is the invention according to claim 1 or 6.
In the above, the optical amplifier is disposed on the incident side of the distributed reflector.

The invention described in claim 8 is claim 1 or 6
In the above, a distributed feedback filter is disposed on the incident side of the distributed reflector.

According to a ninth aspect of the present invention, in the seventh aspect, a polarization mixer is arranged on the incident side of the optical amplifier.

According to a tenth aspect of the present invention, in the eighth aspect, a polarization mixer is arranged on the incident side of the distributed feedback filter.

The eleventh aspect of the present invention is the waveguide according to any one of the first, eighth and tenth aspects, wherein the incident signal light is blocked and the converted light is selectively transmitted to the exit side of the distributed Bragg reflector mirror section. It is characterized in that parts are provided.

[0021]

According to the present invention, with respect to the structure of the bistable wavelength conversion element, the incident side thereof has a much higher reflectance than the narrow band distributed reflection type mirror section on the output side, and the distributed reflection of a wide band. And a first polarized wave, for example, a TM polarized wave (or TE polarized wave) is used as the incident signal light, and a light having a second polarized state orthogonal to the input light, for example, a TE polarized light is used. Wavelength conversion is performed by tuning the narrow-band distributed reflection type mirror section on the emission side from which the output light of the wave (or TM polarization) is emitted.

Since the incident signal light and the output signal light are in polarization states orthogonal to each other, the device can be constructed as a unidirectional device, so that an isolator is not required, and the distributed reflector on the incident side is an optical device. The semiconductor wavelength conversion device of the present invention is suitable for integration into an integrated circuit, and thus is suitable for being integrated alone or together with other optical devices on a semiconductor substrate.

Japanese Unexamined Patent Publication No. 2-152289 discloses an optical amplifying device having a structure similar to that of the present invention. In this optical amplifying device, the reflectance of the distributed Bragg reflector on the input / output side is about 3 to 5% and is equal. That is, since this disclosure relates to the structure of an optical amplifier, it is necessary to allow input light to enter the gain region, and for that purpose, it is necessary to reduce the reflectance of these distributed Bragg reflectors. Therefore, the structure is such that a large amount of output light returns to the incident side. On the other hand, in the present invention, since the structure as the laser oscillator is used,
For that purpose, it is necessary to make the reflectance of the incident side distributed Bragg reflector, that is, (coupling coefficient) × (length), larger than the (coupling coefficient) × (length) of the outgoing side distributed Bragg reflector. Become.

In order to increase the reflection coefficient of the incident side distributed Bragg reflector when the coupling coefficient is small and equal at the input and output ends as disclosed above, the length of this reflector must be increased. However, if the length of the reflector is increased, the transmission loss of light increases, which makes it difficult for the incident light to pass therethrough, which poses a practical problem, and the above-mentioned conventional technique cannot be used for either the optical amplifier or the present invention.

When the coupling coefficient is large and equal at the input and output ends, a single-mode oscillation output cannot be obtained, so that it does not function as a wavelength conversion element. Even in the case of the above-mentioned conventional technique, there is no wavelength conversion function.

[0026]

Embodiments of the present invention will now be described in detail with reference to the drawings.

(Embodiment 1) As a first embodiment of the present invention, FIGS. 1, 2 and 3 show a case where the input light is TM polarized light and the output light is TE polarized light. Here, the same parts as those in FIG. 14 are designated by the same reference numerals. Here, 11 is a distributed reflector having a very high reflectance provided on the incident side of the region 6 between the cladding layers 2 and 6 and having a wide band, for example, an optical waveguide having a multiple quantum well (MQW) structure. It is a distributed reflector having a large coupling coefficient. This distributed reflector 1
The reflection coefficient of 1 is larger than the reflection coefficient of the distributed Bragg reflector 5. Since the cross-sectional shape of the gain region 4 on the plane perpendicular to the light traveling direction is a rectangle whose sides in the thickness direction of the layer are short, the confinement coefficient of the TE polarization in the gain region is that of the TM polarization in the gain region. It becomes larger than the confinement coefficient, and the converted light oscillates in TE polarization.

Even if the cross-sectional structure is not the above-mentioned shape, if the gain region is constituted by a quantum well structure having no strain or compressive strain, the material gain of TE polarization becomes larger than the material gain of TM polarization. Oscillates in TE polarization.

Reference numeral 12 represents the entire distributed reflection type wavelength conversion element constituting the wavelength conversion element of this embodiment.

FIG. 4 shows the transmittance of the distributed reflector 11 with respect to the wavelength. In this case, I by MO-MBE
The MQW layer is formed by laminating nGaAsP as a well layer with a thickness of 10 nm and as a barrier layer with InP having a thickness of 10 nm for 20 cycles. A diffraction grating having a pitch of 0.2 μm and a depth of 0.13 μm was manufactured by direct exposure with an electron beam and a dry etching technique. The coupling coefficient of this diffraction grating is as large as 300 cm ^-1 , which is more than 10 times the coupling coefficient of the diffraction grating of a normal DFB laser. As can be seen from FIG.
For the E polarized wave, a broadband reflection characteristic having a center wavelength of about 1.315 μm and a full width at half maximum of 5 nm was obtained. On the other hand, for TM polarized waves, a reflection band was obtained at a center wavelength of about 1.302 μm. This large wavelength difference of about 13 nm is due to the MQW structure. In a distributed reflector having an ordinary bulk structure and a ridge waveguide structure, this center wavelength difference is about 2.2 nm, which is 1/6 that of the MQW structure.
It is a degree.

Therefore, the signal light wavelength of TM polarization is TE
If it is within the reflection band wavelength for the polarized wave, the signal light can pass through the distributed reflector 11 on the incident side. Therefore, the TM-polarized signal light is absorbed in the saturable absorption region 3, and the loss in this region 3 is modulated. The wavelength conversion element of the present invention is provided with a distributed reflector on both the incident and outgoing sides, and the incident side distributed reflector is a broadband reflector with high reflectance, and is converted by a narrow band distributed reflector on the outgoing side. It is needless to say that the wavelength conversion operation can be performed in the same manner because it has the same structure as the wavelength conversion element described in the related art except that the wavelength conversion is performed by controlling the light wavelength.

The wavelength conversion bandwidth is determined by the tuning bandwidth of the distributed reflector on the output side and can be up to about 4.5 nm. Since the distributed reflector 11 on the incident side functions as a strongly coupled distributed reflector, the reflectance for TE polarized light is 9
A value of 0% or more and a transmittance of 0.01% or less can be taken. This means that the TE oscillating wave hardly leaks to the incident side, so that the isolator which is usually required is not necessary.

Even if a diffraction grating having a small coupling coefficient is used for the distributed reflector, if the distributed reflector is lengthened, TE
Although the reflection coefficient for the polarized output light becomes large and the return to the incident side can be eliminated, the transmittance for the TM polarized incident light decreases due to the loss that unavoidably remains in the waveguide, so the wavelength conversion function is It won't happen.

The larger the coupling coefficient of the diffraction grating of the incident distributed reflector, the smaller the return of the output light to the incident side. Incident When the distributed reflector has a length of 500 μm, the distributed reflection mirror has a length of 300 μm, and the waveguide loss is 10 cm ⁻¹ , the diffraction grating of the distributed reflection mirror has a coupling coefficient of 30 cm ^−1. Coupling coefficient of the diffraction grating of the distributed reflector is 120 cm
If it is larger than ^-1, the ratio of the intensity of the output light emitted to the output side to the intensity of the output light returning to the incident side can be secured at 30 dB or more.

(Embodiment 2) In the second embodiment of the present invention, in the structure similar to that of the first embodiment, TE polarized light is input and TM polarized light is output. In this case,
~ A tensile strained quantum well structure is used for the gain region 4 in FIG.
A semiconductor laser using an extension strained quantum well structure in the gain region can oscillate in TM polarization. Reported by Sato et al. (12th IEEE Internet
ionalSemiconductor Laser
Conference, Davos, Switzerland
and, Sep. 9-14, 1990, pp. 48).

Further, the gain region may have a high mesa structure, and the waveguide cross section may be a rectangle long in the layer thickness direction. In that case, the confinement coefficient of the TM polarized light in the gain region is larger than the confinement coefficient of the TE polarized light in the gain region, so that the converted light oscillates in the TM polarized light.

Here, the effective gain for laser oscillation is
Of course, it is more suitable to use both the strained quantum well structure and the high-mesa structure for TM polarization oscillation, since it is determined by the product of the gain and the confinement coefficient of the material of the active region.

(Embodiment 3) FIGS. 5, 6 and 7 show a third embodiment of the wavelength conversion element of the present invention, which is a frequency switching element integrated with a wavelength selection element into an integrated circuit.

Here, 13 is a distributed feedback filter for wavelength selection arranged between the cladding layers 2 and 6 on the input side of the distributed reflector 11, and 14 is the cladding layer 6 corresponding to the distributed feedback filter 13. Electrode for wavelength selection placed on top of
Reference numeral 5 denotes a polarization mixer arranged on the incident end face of the input light λ ₁ , ..., λ _n .

In this embodiment, the distributed feedback filter 13 is used.
A specific wavelength signal light is selected from a plurality of wavelength-multiplexed signal light by means of and is then incident on the distributed reflector 11, and further converted into light having a polarization state orthogonal to the incident light and having different wavelengths, and emitted. .. Therefore, the distributed feedback filter 1
The tuning band and the transmission band width of No. 3 are similar to the wavelength conversion band and the reflection band width on the emission side.

The distributed feedback filter 13 can also be an optical amplifier that can gain gain in the same manner as the DFB laser structure. In that case, it is preferable that the gain of the incident light with respect to the polarized wave (for example, the TE polarized wave) be increased. That is, in the case of TE polarization input, it is preferable to use a DFB structure having no distortion or a compression distortion superlattice structure. On the other hand, in the case of TM polarization input, it is preferable to use the DFB structure of the extension strain superlattice structure. Alternatively, or
The diffraction grating is formed in a plane perpendicular to the substrate, which is a plane perpendicular to the normal diffraction grating plane, that is, the diffraction grating 1 shown in the figure.
It is desirable that 3 has a shape rotated by 90 ° about the optical axis as a rotation axis. In this case, the waveguiding layer may be either a bulk layer or a multiple quantum well layer.

Of course, it does not matter at all that an optical amplifier is provided separately from the distributed feedback filter 13.

When the incident signal light does not have a polarization (for example, TM polarization) component set so as to pass through the incident side distributed Bragg reflector, the polarization mixer 15 It is necessary to generate a polarized wave component.
This polarization mixer has an S processed into a simple diffuser structure.
It can be composed of an iO ₂ film.

(Embodiment 4) FIGS. 8, 9 and 10 show a fourth embodiment of the device of the present invention in which the input light is TM polarized light.
The case where the output light is TE polarized light is shown, where 16 is a metal film disposed on the cladding layer 6 on the emission end side, and 17 extends beyond the active layer of the distributed Bragg reflector 5 on the emission end side. Is the output waveguide layer. When the TM polarized light is used as the incident signal light, the wavelength-converted TE polarized light and the incident signal light as the output signal light pass through and are emitted as they are. Therefore,
Only the TM polarization needs to be attenuated. Therefore, in this embodiment, a metal film is loaded on the output waveguide layer.

This method is usually used for separating the TE polarized wave and the TM polarized wave in the optical IC substrate, and it is easy to obtain isolation of 20 dB or more.

When the input light is the TE polarized light and the output light is the TM polarized light, the output waveguide extending in front of the distributed Bragg reflector 5 shown in FIGS. ,
A TM polarization selective waveguide may be provided. Such an optical waveguide is disclosed in Y. Reported by Suzuki et al. (Y. Suzuki et al., Appl. Phy.
s. Lett. Vol. 57 pp. 2745 (199
0)).

Although the semiconductor optical waveguide is made of an InP-based material in the above embodiments, the present invention is not limited to this example, and a GaAs-based material may be used, for example. Furthermore, as for the conductivity type of each semiconductor material, the p-type and the n-type in the above-described embodiments can be replaced with the opposite conductivity type. In addition, although the optical waveguide structure is a wedge type in the above-described embodiments, the present invention is not limited to this example, and it goes without saying that it may be a buried type optical waveguide.

In the element of the present invention, a distributed Bragg reflector using a diffraction grating having different coupling coefficients on the input and output sides is used. Here, a preferable range of the coupling coefficient K of this reflector will be examined.

For this purpose, the model shown in FIG. 11 is used as the asymmetric K distributed reflector. Here, each parameter is defined as follows.

Coupling coefficient of input side distributed reflector: K _r Length of input side distributed reflector: L _r Coupling coefficient of output side distributed reflector: K _f Length of output side distributed reflector: L _f = 300 μm Waveguide loss: α = 10 cm ⁻¹ Power at output end of output light: P _f Power at input end of output light: P _r (return light power) Isolation ratio before and after: r = (P _r / P _f FIG. 12 shows the results of the relationship between the required values of K _f and K _r when the isolation ratio is set to −30 dB, using L _r as a parameter (L _f is calculated at 300 μm). L
_{If r} is 300 μm, K _r is 1 when K _f is 30 cm ^−1.
If it is 50 cm ^-1 or more, the isolation ratio is -30 dB.
It becomes better (smaller) than (1/1000).

FIG. 13 shows that L _r is 300 μm (L _f is 300
It shows how the isolation ratio changes depending on the relationship between K _r and K _f when fixed to μm). K
_{When f} is 300 cm ^-1 , K _r is 70 cm ^-1 , and -10 dB,
It becomes -30 ^dB at 145 cm ^-1 .

From the above consideration, the preferable range of the coupling coefficient K is L _f = 300 μm, L _r = 300 μm,
When α = 10 cm ⁻¹ , the isolation is about 10 dB or more, that is, K _f <30 cm ⁻¹ K _r > 70 cm ⁻¹ . Further, as a more preferable range, under the same conditions, the isolation is about 30 dB or more, and K _f <30 cm ⁻¹ K _r > 150 cm ⁻¹ .

[0053]

As described above, according to the present invention, with respect to the structure of the bistable wavelength conversion element, the incident side thereof has a reflectance higher than that of the narrow band distributed reflection type mirror section on the emitting side. The wavelength conversion is performed by arranging a distributed reflector of high and wide bandwidth, making the polarizations of the incident signal light and output signal light orthogonal, and tuning the narrow-band distributed reflection type mirror section on the output side. Therefore, there are the following advantages.

(1) By using the light of the polarization orthogonal to the output signal light as the incident signal light, the configuration as a unidirectional device becomes possible, and it is not necessary to insert an isolator.

(2) It can be easily integrated on the same substrate alone or together with various optical elements.

(3) Since the reflectance of the distributed reflector on the incident side is very high, the converted light hardly leaks to the incident side, so that the wavelength conversion efficiency is high and therefore the conversion gain is large.
As a result, it is possible to obtain emitted light with a high output level.

[Brief description of drawings]

FIG. 1 is a vertical sectional view taken along line II-II ′ showing a first embodiment of a semiconductor wavelength conversion device of the present invention.

FIG. 2 is a cross-sectional view taken along the line II ′ of the first embodiment of the semiconductor wavelength conversion device of the present invention.

FIG. 3 is a perspective view showing a first embodiment of the semiconductor wavelength conversion device of the present invention.

FIG. 4 is a characteristic diagram showing the transmittance with respect to wavelength of the strong coupling distributed reflector of the first embodiment.

FIG. 5 is a vertical sectional view taken along the line II-II ′ showing the third embodiment of the present invention.

FIG. 6 is a cross-sectional view taken along the line II ′ of the third embodiment of the present invention.

FIG. 7 is a perspective view showing a third embodiment of the present invention.

FIG. 8 is a vertical sectional view taken along the line II-II ′ showing the fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view taken along the line II ′ of the fourth embodiment of the present invention.

FIG. 10 is a perspective view showing a fourth embodiment of the present invention.

FIG. 11 is a model diagram of an element of the present invention for explaining how to determine a coupling coefficient in the present invention.

FIG. 12 is a characteristic diagram showing the relationship between the values of K _f and K _r used in determining the coupling coefficient in the present invention, using L _r as a parameter.

FIG. 13 is a characteristic diagram showing the relationship between the values of K _f and K _r used in determining the coupling coefficient in the present invention, using L _r as a parameter.

FIG. 14 is a vertical cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 n-InP substrate 2 n-clad layer 3 saturable absorption region 4 gain region 5 distributed reflection mirror section 6 p-clad layer 7 saturable absorption region electrode 8 gain region electrode 9 tuning electrode 10 electrode 11 distributed reflection Device 12 Wavelength conversion element 13 Distributed feedback filter 14 Wavelength selection electrode 15 Polarization mixer 16 Metal film 17 Output waveguide layer

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsuru Naganuma 1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Shingo Uehara 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corp. (72) Inventor Katsuhiko Kurumada 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corp.

Claims (1)

Claim: What is claimed is: 1. A distributed reflection structure comprising a saturable absorption region, a gain region, and a diffraction grating for selecting a converted light wavelength on a semiconductor substrate via a first cladding layer. And a saturable absorption region, the gain region, and the distributed reflection type via a second cladding layer on the saturable absorption region, the gain region, and the distributed reflection type mirror unit. In a semiconductor wavelength conversion element corresponding to a mirror part and having first, second and third electrodes arranged separately from each other, in the light incident side of the saturable absorption region, the diffraction grating of the distributed reflection type mirror part is provided. A distributed reflector that has a diffraction grating with a coupling coefficient larger than the coupling coefficient and that transmits the incident signal light in the first polarization state is disposed, and the distributed reflection type mirror unit is arranged so as to be orthogonal to the first polarization state. Extracts converted light in two polarization states And a semiconductor wavelength conversion device, wherein a wavelength of the converted light and to control the current injected from the third electrode. 2. The first polarization state is a TM polarization state, the second polarization state is a TE polarization state, and the waveguide cross section of the gain region is a rectangle short in the layer thickness direction. As a result, the confinement coefficient of the TE polarized light inside the gain region is made larger than the confinement coefficient of the TM polarized light inside the gain region to enable the conversion light extraction of the TE polarized state. The semiconductor wavelength conversion device according to claim 1. 3. The first polarization state is a TE polarization state, the second polarization state is a TM polarization state, and the waveguide cross-sectional shape of the gain region is a rectangle long in the layer thickness direction. As a result, the confinement coefficient of the TM polarized wave inside the gain region is made larger than the confinement coefficient of the TE polarized wave inside the gain region to enable the conversion light extraction of the TM polarized state. The semiconductor wavelength conversion device according to claim 1. 4. The first polarization state is a TM polarization state, the second polarization state is a TE polarization state, and the gain region has a quantum well structure having a compressive strain with a strain amount of 0 or more. 2. The semiconductor wavelength conversion device according to claim 1, wherein the material gain of the TE polarized light is made larger than the material gain of the TM polarized light so that the converted light in the TE polarized state can be extracted. 5. The first polarization state is a TE polarization state, the second polarization state is a TM polarization state, and the gain region is constituted by a quantum well structure having extension strain.
3. The semiconductor wavelength conversion device according to claim 2, wherein the material gain of M polarization is made larger than the material gain of TE polarization to enable conversion light extraction of said TM polarization state. 6. The semiconductor wavelength conversion device according to claim 1, wherein the optical waveguide layer of the distributed reflector has a multiple quantum well structure. 7. The semiconductor wavelength conversion device according to claim 1, wherein an optical amplifier is arranged on the incident side of the distributed reflector. 8. The semiconductor wavelength conversion device according to claim 1, further comprising a distributed feedback filter disposed on the incident side of the distributed reflector. 9. The semiconductor wavelength conversion device according to claim 7, wherein a polarization mixer is arranged on the incident side of the optical amplifier. 10. The semiconductor wavelength conversion device according to claim 8, wherein a polarization mixer is disposed on the incident side of the distributed feedback filter. 11. The emission side of the distributed Bragg reflector type mirror,
11. The semiconductor wavelength conversion element according to claim 1, further comprising a waveguide section that blocks the incident signal light and selectively transmits the converted light.