JPH04249368A - Surface type semiconductor light switch - Google Patents

Abstract

PURPOSE:To obtain a surface type semiconductor light switch which operates with low switching energy and produces a high light output with high speed response by a method wherein a hetero junction bipolar photo transistor for receiving an incident light and a surface emitting laser for outputting a laser light are so formed as to be laminated in series on a same substrate. CONSTITUTION:In 2 mirror portions constituting a resonator of a surface light- emitting laser, 2 types of semiconductor AlAs/Al0.05Ga0.95As having different refractive indexes and in which the thickness of each layer is odd times of 1/4 of laser resonant wave length are laminated to provide a distribution brag reflection type mirror (DBR). Here, a p<+>-Al0.2Ga0.8As clad layer 13, an n<+>-Al0.9 Ga0.7As clad layer 15 and a p<+>-Al0.1Ga0.9As ohmic layer 11 are provided. Then, a laser light released to the side of a hetero junction bipolar light transistor is absorbed into a p-In0.05Ga0.95As base layer 18. Further, an incident light is reflected on a DBR mirror to be absorbed while it passes through the base layer 18 twice.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar semiconductor optical switch that operates with low switching energy, has high-speed response, and has large optical output.

0002

[Prior Art] This type of conventional optical switch is shown in FIGS. 7 and 8.
, will be explained using FIGS. 9 and 10. An example of a semiconductor material is AlGaAs (partly InGaAs). FIG. 7 is a cross-sectional view of the device.
ht Emitting Diode: Light emitting diode) and HPT (Heterojunction B
This is a stack of ipolar photo transistors (heterojunction bipolar phototransistors). 3 in the LED section is a GaAs active layer, which has a wavelength of 0.
It emits light of 88 μm. HPT part 5 n-Al
The 0.3 Ga0.7 As layer is the collector layer, and the 6
The p-In0.05Ga0.95As layer is the base layer and absorbs light from the LED. 7 n-Al 0.3
The Ga0.7As layer acts as an emitter layer. Light input enters from the emitter side of the HPT, and light output is extracted from the LED side.

Next, the principle of operation will be explained using FIG. 8. When there is no optical input, the resistance of the HPT is high and no current flows through the circuit. When light enters the HPT from the emitter side, it is absorbed by the base layer and current flows through the circuit. As a result, the LED emits light, and light is emitted from both sides of the LED. HP
The light emitted to the T side is absorbed by the base and becomes more and more
More current flows and the light intensity from the LED becomes even stronger. Therefore, a kind of positive feedback occurs, and the switch is kept in an on state (with optical output). FIG. 9 schematically shows the current/voltage characteristics when there is no optical input, and FIG. 10 schematically shows the current/voltage characteristics when there is optical input. When there is no light input as shown in FIG. 9, if the voltage is appropriately biased and a light pulse is input, the switch is switched from off to on, and the on state is maintained. on
To turn off the state, lower the bias voltage.

[0004] In this case, since LEDs are used for the light emitting part, the light output has poor directivity and spreads out. Therefore, when this kind of elements are two-dimensionally integrated and the output light is used to drive the next stage device, unnecessary There was a problem that the elements were also driven together. Furthermore, since it was an LED, the light output was weak and there was a limit to the driving ability of the next stage. Furthermore, since it is an LED, there is a problem in that the modulation speed is low, at most several hundred MHz.

[0005]

[Problems to be Solved by the Invention] An object of the present invention is to replace the LED in the light emitting section with a surface emitting laser,
The aim is to obtain good directivity and large optical output power, and to make the modulation speed as high as 1 GHz or higher. Also, HPT
By providing a reflective layer in a portion adjacent to the optical fiber, low input optical power operation can be realized.

[0006]

[Means for Solving the Problems] The structure of the present invention is as follows.

A heterojunction bipolar optical transistor that receives incident light and a surface emitting laser that outputs laser light are stacked in series on the same substrate, and a first surface of the semiconductor substrate adjacent to the surface emitting laser is formed. and a second surface opposite to the first surface, electrodes (42, 41) are formed on the first surface and the second surface, and a predetermined bias is applied between both electrodes, and the second surface is A surface-type semiconductor optical switch, characterized in that a heterojunction bipolar optical transistor receives light input from the surface, and obtains a laser output of a surface-emitting laser from the first surface, or alternatively,

[0008] A planar semiconductor optical switch configured by sequentially stacking a heterojunction bipolar optical transistor and a surface emitting laser formed on a predetermined substrate (8),
The surface emitting laser includes a first ohmic semiconductor layer (1) which has a first conductivity type and is transparent to the first light.
1), a second semiconductor layer that has a first conductivity type and is transparent to the first light, and a second semiconductor layer that has a second conductivity type and is transparent to the first light;
The third semiconductor layer is transparent to light and has a refractive index different from that of the second semiconductor, and the thickness of each layer is an odd multiple of 1/4 of the wavelength of the first light. 2. A first light reflecting layer (
12) and a fifth semiconductor active layer (
14) A fourth semiconductor cladding layer (13) having a lower refractive index and transmittance to the first light, and an impurity that provides the first or a second conductivity type opposite to the first conductivity type. A fifth semiconductor active layer (14) that is not intentionally added and emits the first light by recombination of electrons and holes in the layer, and a fifth semiconductor active layer that has a second conductivity type. a sixth semiconductor cladding layer (15) having a refractive index lower than that of the layer (14) and transparent to the first light; and a sixth semiconductor cladding layer (15) having a second conductivity type and transparent to the first light. an eighth semiconductor layer that has a second conductivity type, is transparent to the first light, has a different refractive index from the seventh semiconductor layer, and has a thickness of A reflective layer (16) for the first light, which is formed by alternately laminating a plurality of pairs or more of seventh and eighth semiconductor layers having a thickness equal to an odd multiple of 1/4 of the wavelength of the first light; , the heterojunction bipolar phototransistor has a second conductivity type,
a ninth semiconductor collector layer (17) that is transparent to the first and second lights; and a tenth semiconductor collector layer (17) that has the first conductivity type and is absorbent to the first and second lights. a semiconductor base layer (18), and an eleventh semiconductor emitter layer (19) having a second conductivity type and transmitting to the first and second wavelengths of light, The first ohmic semiconductor layer (11) and the emitter layer (19)
) has a metal electrode (42) that applies a predetermined bias between them.
, 41), comprising a light input window on the emitter side of the heterojunction bipolar phototransistor, and a laser output window on the surface of the surface emitting laser opposite to the heterojunction bipolar phototransistor. A surface type semiconductor optical switch, or also,

The eleventh emitter layer (19, 31) of the heterojunction bipolar optical transistor and the substrate (8)
a twelfth semiconductor layer having a second conductivity type between them and being transparent to the first and second lights; and a twelfth semiconductor layer having a second conductivity type and transmitting the first and second lights. The twelfth and third semiconductor layers each have a thickness that is an odd multiple of 1/4 of the wavelength of the second light. A planar semiconductor optical switch characterized by interposing a second light reflecting layer (30) in which a plurality of pairs or more of 13 semiconductor layers are alternately laminated, or alternatively,

The heterojunction bipolar phototransistor has a second conductivity type between the eleventh emitter layer (19, 31, 32) and the substrate (8), and A planar semiconductor optical switch characterized by having transparency and having a mirror emitter layer of a predetermined thickness interposed therebetween;

[0011] A surface-type semiconductor optical switch is constructed by sequentially laminating a heterojunction bipolar optical transistor formed on a predetermined substrate (26) and a surface-emitting laser, the surface-emitting laser being a first a first ohmic semiconductor layer (22) that has a conductivity type, is transparent to the first light, and has a refractive index smaller than that of the third semiconductor layer; , a second semiconductor cladding layer (15') that is transparent to the first light and has a refractive index smaller than that of the third semiconductor active layer (14), and the first or first conductivity type. Do not intentionally add impurities that give the opposite second conductivity type.
A third semiconductor active layer (14) that emits the first light by recombination of electrons and holes within the layer, and a third semiconductor active layer (14) that has a second conductivity type and a higher refractive index A fourth semiconductor cladding layer (13
'), a fifth semiconductor layer that has a second conductivity type and is transparent to the first light, and a fifth semiconductor layer that has a second conductivity type and is transparent to the first light;
The fifth and sixth semiconductor layers each have a thickness that is an odd multiple of 1/4 of the wavelength of the first light. The heterojunction bipolar phototransistor is formed by sequentially laminating a first light reflecting layer (12') in which a plurality of pairs or more of semiconductor layers are alternately laminated. A seventh semiconductor collector layer (23
), an eighth semiconductor base layer (24) having a first conductivity type and absorbing to the first and second lights; The first ohmic semiconductor layer (25) is sequentially laminated from the ninth semiconductor emitter layer (25) that is transparent to the second wavelength of light.
22) and the emitter layer (25) are provided with metal electrodes (42, 41) for applying a predetermined bias between them, and an optical input window is provided on the emitter side of the heterojunction bipolar phototransistor. A planar semiconductor optical switch characterized in that the laser output is obtained from the opposite side of the heterojunction bipolar optical transistor, or alternatively,

[0012] The first ohmic semiconductor layer (22)
A planar semiconductor optical switch, characterized in that a reflective film (21) for the first light made of a metal thin film is provided thereon as an electrode, or alternatively,

A laser output window is formed on the electrode (41) formed on the first ohmic semiconductor layer, and a laser output window is formed on the first ohmic semiconductor layer (22) in the laser output window. A plurality of pairs or more of a first dielectric and a second dielectric having a different refractive index from the first dielectric are laminated alternately so that the thickness of each layer is an odd multiple of 1/4 of the wavelength of the first light. A planar semiconductor optical switch characterized by comprising a dielectric laminated layer serving as a reflective layer for the first light formed by the process, or alternatively,

[0014] A surface-type semiconductor optical switch is constructed by sequentially stacking a surface-emitting laser and a heterojunction bipolar optical transistor formed on a predetermined substrate (36), wherein the surface-emitting laser is or a semiconductor substrate (36) of a second conductivity type opposite to the first conductivity type, or a semi-insulating semiconductor substrate (36), and an impurity that gives the first conductivity type or a second conductivity type opposite thereto is intentionally added. Alternatively, the first semiconductor layer has the second conductivity type and is transparent to the first light, and an impurity that gives the first conductivity type or the opposite second conductivity type is intentionally added. It is composed of a second semiconductor layer that is not added to the semiconductor layer or has a second conductivity type, is transparent to the first light, and has a refractive index different from that of the first semiconductor layer, and each has a thickness of A reflective layer (35) for the first light, in which a plurality of pairs or more of first and second semiconductor layers each having an odd multiple of 1/4 of the wavelength of the first light are laminated alternately, and a first conductivity type. and a third semiconductor layer (34) that is transparent to the first light.
and a fourth semiconductor cladding layer (13) that also has the first conductivity type and is transparent to the first light, and an impurity that gives the first or second conductivity type is intentionally added. Without,
A fifth semiconductor active layer (14) that emits first light by recombining electrons and holes, and a sixth semiconductor that has a second conductivity type and is transparent to the first light. a seventh semiconductor layer having a second conductivity type and transparent to the first light; and a seventh semiconductor layer having a second conductivity type and transparent to the first light. an eighth semiconductor layer having a refractive index different from that of the seventh semiconductor layer, each having a thickness of 1 wavelength of the first light.
The heterojunction bipolar optical transistor is configured by sequentially laminating a first light reflecting layer (16) in which a plurality of pairs or more of seventh and eighth semiconductor layers of odd multiples of /4 are laminated, and
a ninth semiconductor collector layer (17) having a second conductivity type and transmitting the first and second lights; and a ninth semiconductor collector layer (17) having the first conductivity type and transmitting the first and second lights. a tenth semiconductor base layer (18) that is absorbent to the light; and an eleventh semiconductor emitter layer (32) that has the second conductivity type and is transparent to the first and second light. and a metal electrode (42) having a light input window on the eleventh semiconductor emitter layer (32) via a mirror emitter layer (33), and the third semiconductor emitter layer (32). Layer (3
4) The other electrode (41) is provided on the top, a predetermined bias is applied between both electrodes, and the laser output is obtained from the side of the substrate (36) opposite to the light input window. Features: Surface-type semiconductor optical switch.

[0015]

[Example] AlGaAs is a typical semiconductor material
An example of the present invention will be described using (partly InGaAs) as an example.

FIG. 1 shows that the two mirror parts constituting the resonator of a surface emitting laser have different refractive indexes, and the thickness of each layer is an odd multiple of 1/4 of the laser oscillation wavelength (the wavelength is a crystal Two types of semiconductors AlAs/Al0.05 (wavelength of light inside)
DBR (Distributed Bragg) laminated with Ga0.95As (thickness 73 nm/60 nm)
Reflector: Distributed Bragg reflection mirror) is used. Generally, when 20 or more pairs are laminated, a mirror with a reflectance of 98% or more can be obtained. Also,
It has a reflectance of 90% or more over a wide wavelength range of about ± (plus/minus) 50 nm from the center wavelength. In this example laser, 13 is p+ -Al0.2 G
a0.8 As cladding layer and 15 are n+ -Al
0.9 Ga0.7 As acts as a cladding layer, 11
The p+ -Al 0.1 Ga0.9 As layer is a thin ohmic layer doped with p-type impurities at a high concentration to lower the contact resistance of the p-side electrode. This planar laser uses 14 GaAs layers as active layers and oscillates at a wavelength of 880 nm.

[0017] The laser beam emitted to the HPT side
T p-In 0.05Ga0.95As base layer
(Thickness: 0.3 μm, wavelength of light corresponding to band gap λg = 0.90 μm, carrier concentration: 1×1017 cm
-3) Absorbed by. The wavelength of the input light to the HPT is
It is not necessarily necessary to match the laser oscillation wavelength, and HPT
Any wavelength that is absorbed by the base layer may be used. DBR
As mentioned earlier, the mirror has a large reflectance over a relatively wide spectral width, so the incident light is reflected by the DBR mirror of the surface-emitting laser and passes through the base layer twice, as shown by the dotted line in Figure 1. absorbed between.

In order for the base layer to efficiently absorb input light, the thickness needs to be 1 μm or more, assuming that the absorption coefficient for light with energy above the band gap is 10 4 cm −3 . On the other hand, in order to increase the response speed of a transistor, it is essential to make the base width as thin as possible. Therefore, if the input light is reflected by the DBR mirror and passes through the base layer twice as in this embodiment, the base width can be made thinner and the speed can be increased. Furthermore, since the light passes through the base layer twice, the input light intensity required for the optical switch can be reduced.

Note that in this example, the Ga
Although the As active layer thickness is relatively thick at 0.6 μm, the DBR mirror spacing has been actively researched recently. ) may also be short-cavity surface-emitting lasers, as described, for example, in the paper by Yamamoto et al., Applied Physics 59 (1990) 1204). Of course, the above also applies to the following examples, although they are not specifically mentioned.

[0020] Current/voltage characteristics and on-off of the element
The relationship between the state and the optical input is almost the same as the characteristics in FIGS. 9 and 10.

The embodiment shown in FIG. 2 has a structure in which the input light passes through the base layer two or more times so that light is sufficiently absorbed even if the base layer is made thin, that is, a DBR is installed on the emitter side of the HPT. It is equipped with a mirror. When the reflectance of this mirror is increased, it is necessary to select the wavelength strictly in order to allow light to enter the HPT (for example, Δλ<0.4 nm when the reflectance is 90% or more). In order to relax this constraint, the reflectance of the mirror in this area is usually lowered to about 30% to form an asymmetric mirror resonator (the reflectance of the other mirror, here the DBR of the surface emitting laser, is 95% or more). In this way, the incident light passes through the base layer multiple times, increasing absorption efficiency. Furthermore, since the base layer can be made thinner, it can contribute to faster HPT.

In the embodiment shown in FIG. 2, D on the emitter side
BR is made of multilayer film, but n+ -A without anti-reflection film
l 0.3 Ga0.7 Even with a single layer of As, the reflectance is 30%
It can be achieved to some extent. An example at this time is shown in FIG. Figure 2
In the embodiment shown in FIG. 3, since the input light travels back and forth within the HPT many times, there is a concern that the lifetime of the photon resonator will be lengthened. However, in reality, since the base layer acts as an absorption layer, the resonator life is less than 1 ps and can be ignored.

Note that the current/voltage characteristics and on-
The relationship between the off state and the optical input is almost the same as the characteristics in FIGS. 9 and 10.

In the embodiment shown in FIG. 4, since the p+ semiconductor DBR of a surface emitting laser generally has a high resistance, this DBR is
Using a 40-200 nm thick Ag thin film instead,
This type serves both as a reflecting mirror and as an electrode. Since the reflectance of the Ag thin film is 95% or more when the thickness is 40 nm or more, an efficient surface-emitting laser can be realized.

Note that the current/voltage characteristics and on-
The relationship between the off state and the optical input is almost the same as the characteristics in FIGS. 9 and 10.

The embodiment shown in FIG.
+ Since the resistance of the semiconductor DBR is high, TiO 2
/SiO 2 dielectric DBR mirror. For this reason, the p-side electrode is made into a mesa shape as shown in FIG.
Take it out from the s-ohmic layer. Depending on the oscillation wavelength of the laser, a dielectric material having a larger refractive index difference, for example, a-Si/SiO 2 may be used as the dielectric material.

As described above, in the embodiments shown in FIGS. 4 and 5, the relationship between the current/voltage characteristics of the element, the on-off state, and the optical input is as follows.
The characteristics are almost the same as those in FIGS. 9 and 10.

Note that, as in the embodiments shown in FIGS. 2 and 3,
It is also possible to provide a reflective film on the emitter side of the HPT in the embodiments shown in FIGS. 4 and 5 so that the input light passes through the light absorption layer (base) many times.

Generally, a p+ type semiconductor DBR has a high resistance and a large light absorption loss for laser light. Therefore, in order to obtain a high-performance surface emitting laser, there are some embodiments that do not use p+ -DBR. In the embodiment of FIG. 6, the metal electrode terminal 41 is taken out from the middle, and instead of the p+ -DBR,
An i- or n-type semiconductor DBR layer 35 was used. Laser light output is taken out from the GaAs substrate 36 side. In FIG. 6, the metal electrode 41 is directly p+ -Al0.3 Ga0.
Although it is attached to the 7As layer 34, a p+ -GaAs layer may be sandwiched in between to obtain good ohmic resistance.

Furthermore, in FIG. 6, the polarity of the GaAs substrate is p.
It may be any type, n-type, or semi-insulating (SI).

In the embodiments described above, AlGaAs was used as an example, but in addition to this, GaAs which emits light in the 0.9 μm band
InGaAs/AlGaAs strained semiconductor on s substrate,
I on an InP substrate that emits light in the 1.0-1.5 μm band
An nGaAsP-based semiconductor or the like may also be used. In these material systems, since the crystal substrate does not absorb incident light or laser light, there is no need to remove the crystal substrate when manufacturing devices from a wafer, thereby simplifying the process.

[0032]

As explained above, when a surface emitting laser is used in the light emitting section, a high directivity and high power optical output can be obtained, and the switching speed can also be increased to 1 GHz or more. In addition, since there is a reflective layer adjacent to the HPT,
Since input light from the emitter side of the device passes through the light absorption layer (base) many times, the base layer can be made thinner and higher speeds can be achieved. Furthermore, the input optical power required for the optical switch can also be reduced.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention in which a semiconductor DBR is used as a mirror of a surface emitting laser.

[Figure 2] Semiconductor DBR in part of the emitter layer of HPT
An embodiment of the present invention incorporating a mirror.

FIG. 3 is an embodiment of the present invention in which a mirror with low reflectivity is provided on the emitter layer side of the HPT.

FIG. 4 is an embodiment of the present invention in which a metal thin film is used for one of the mirrors of a surface emitting laser.

[Figure 5] Dielectric DBR on one side of the mirror of the surface emitting laser
An embodiment of the present invention using a mirror and a semiconductor DBR mirror on the other side.

FIG. 6 is an embodiment in which an i- or n-type semiconductor DBR is used instead of a p+-DBR mirror of a surface emitting laser.

FIG. 7 is an example of a conventional surface-type semiconductor optical switch.

FIG. 8 shows the operating principle of a conventional planar semiconductor optical switch.

FIG. 9 shows the current/voltage characteristics of a conventional planar semiconductor optical switch element without optical input.

FIG. 10 shows the current/voltage characteristics of a conventional planar semiconductor optical switch element with optical input.

[Explanation of symbols]

1 p+ -GaAs (carrier concentration, 2×10
18cm-3 or more) 2 p+ -Al 0.3 G
a 0.7As (thickness 0.8 μm, carrier concentration 5
×1017cm-3) 3 GaAs active layer (thickness 0.6 μm, λg=0
．． 88 μm) 4 n+ -Al 0.3 Ga0.
7 As (thickness 0.6 μm, carrier concentration 1×101
8cm-3) 5 n-Al 0.3 Ga0.7 As (thickness 0.
6 μm, carrier concentration 1 x 1017 cm-3) 6 p-In 0.05Ga0.95As (thickness 0
．． 3 μm, λg=0.90 μm, carrier concentration 1×1
017cm-3)7 n-Al 0.3 Ga0.7
As (thickness 1.5 μm, carrier concentration 5×101
7cm-3) 8 n+ -GaAs substrate (carrier concentration>2×
1018cm-3) 11 p+ -Al 0.1 G
a0.9 As (thickness 10 nm, carrier concentration 1×1
018cm-3) Ohmic layer 12 p+ -AlAs/Al0.05Ga0.95
As DBR (thickness 73nm/60nm) 12'n+ -AlAs/Al0.05Ga0.95A
s DBR (thickness 73 nm/60 nm) 13 p+ -Al 0.2 Ga0.8 As (
Thickness: 3 μm) Cladding layer 13'n+ -Al 0.2
Ga0.8 As (thickness 3 μm) cladding layer 14
GaAs active layer (thickness 0.6 μm) 15 n+
-Al 0.3 Ga0.7 As (thickness 0.5 μm
) Cladding layer 15'p+ -Al 0.3 Ga0.7 As (thickness 0.5 μm) Cladding layer 16 n+ -AlAs/Al0.05Ga0.95
As DBR (thickness 73 nm/60 nm) 17 n-Al 0.3 Ga0.7 As (thickness 0.6 μm, carrier concentration 1 x 1017 cm-3)
Collector layer 18 p-In 0.05 Ga 0.9
5As (thickness 0.3 μm, λg=0.90 μm, carrier concentration 1×1017 cm−3) base layer 19
n-Al 0.2 Ga 0.8 As (thickness 1.
5 μm, carrier concentration 5 x 1017 cm-3) Emitter layer 20 Anti-reflection film 21 Ag film (thickness 40-200 nm) 22
p+ -Al 0.1 Ga0.9 As ohmic layer (thickness 10 nm) 23 n+ -Al 0.3
Ga0.7 As collector layer 24 p-In 0.0
5Ga0.95As base layer 25 n-Al 0.1
Ga0.9 As emitter layer 26 n+ -GaA
s Substrate 30 n+ -AlAs/Al0.05Ga0.95
As DBR (thickness 72nm/60nm) 31n
-Al0.2Ga0.8As emitter layer 32
n-Al 0.1 Ga0.9 As emitter layer 33
n-Al 0.3 Ga0.7 As emitter layer 34
p+ -Al 0.3 Ga0.7 As35
i or n-AlAs/Al0.05 Ga 0.95A
s DBR36 n or p or SI (semi-insulating) G
aAs substrate 40 TiO 2 /SiO2 dielectric D
BR Mirror 41 Metal electrode (electrode for surface emitting laser) 42 Metal electrode (emitter electrode)

Claims (8)

[Claims] 1. A heterojunction bipolar optical transistor that receives incident light and a surface emitting laser that outputs laser light are stacked in series on the same substrate. and a second surface opposite to the first surface, electrodes are formed on the first surface and the second surface, and a predetermined bias is applied between both electrodes, and a bias is applied from the second surface. 1. A surface-type semiconductor optical switch, characterized in that an optical input is received by a heterojunction bipolar optical transistor, and a laser output of a surface-emitting laser is obtained from the first surface. 2. A surface-type semiconductor optical switch configured by sequentially stacking a heterojunction bipolar optical transistor and a surface-emitting laser formed on a predetermined substrate, the surface-emitting laser comprising a first A first ohmic semiconductor layer that has a conductivity type and is transparent to the first light; and a second semiconductor layer that has the first conductivity type and is transparent to the first light. and a third semiconductor layer having a second conductivity type, transparent to the first light, and having a different refractive index from the second semiconductor, and each layer has a thickness similar to that of the first light. 1/ of the wavelength of
a first light-reflecting layer in which a plurality of pairs or more of second and third semiconductor layers each having a thickness of an odd number of times 4 are alternately laminated; and a fifth semiconductor active layer having a first conductivity type; A fourth semiconductor cladding layer that has a small refractive index and is transparent to the first light, and an impurity that provides the first or a second conductivity type opposite to the first conductivity type is not intentionally added. , a fifth semiconductor active layer that emits first light by recombining electrons and holes within the layer;
a sixth semiconductor cladding layer that has a second conductivity type, has a refractive index lower than that of the fifth semiconductor active layer, and is transparent to the first light; a seventh semiconductor layer that is transparent to light, and has a second conductivity type;
It is composed of an eighth semiconductor layer that is transparent to the first light and has a different refractive index from the seventh semiconductor layer, and has a thickness that is an odd multiple of 1/4 of the wavelength of the first light. The heterojunction bipolar phototransistor has a structure in which a plurality of pairs of seventh and eighth semiconductor layers are alternately stacked and a reflective layer for first light, and the heterojunction bipolar phototransistor has a second conductivity type; and a ninth semiconductor collector layer that is transparent to the second light;
a tenth semiconductor base layer having a first conductivity type and absorbing to the first and second light; and a tenth semiconductor base layer having a second conductivity type and absorbing to the wavelengths of the first and second lights. and an eleventh semiconductor emitter layer that is transparent to the semiconductor emitter layer.
The first ohmic semiconductor layer and the emitter layer are provided with a metal electrode for applying a predetermined bias between them, and an optical input window is provided on the emitter side of the heterojunction bipolar phototransistor. A planar semiconductor optical switch characterized by having a laser output window on a surface opposite to a junction bipolar optical transistor. 3. A twelfth emitter layer having a second conductivity type and transparent to the first and second lights is disposed between the eleventh emitter layer of the heterojunction bipolar phototransistor and the substrate. and a thirteenth semiconductor layer, which has a second conductivity type, is transparent to the first and second light, and has a refractive index different from that of the twelfth semiconductor. A reflecting layer for the second light is interposed, which is formed by alternately laminating a plurality of pairs or more of 12th and 13th semiconductor layers having a thickness that is an odd multiple of 1/4 of the wavelength of the second light. The planar semiconductor optical switch according to claim 2. 4. A layer between an eleventh emitter layer of the heterojunction bipolar phototransistor and the substrate has a second conductivity type and is transparent to the first and second light; 3. The planar semiconductor optical switch according to claim 2, further comprising a mirror emitter layer having a predetermined thickness. 5. A surface-type semiconductor optical switch configured by sequentially stacking a heterojunction bipolar optical transistor and a surface-emitting laser formed on a predetermined substrate, the surface-emitting laser comprising a first a first ohmic semiconductor layer that has a conductivity type, is transparent to the first light, and has a refractive index smaller than that of the third semiconductor layer;
a second semiconductor cladding layer that is transparent to the first light and has a refractive index smaller than that of the third semiconductor active layer; and a first or second conductivity type opposite to the first conductivity type. a third semiconductor active layer that emits the first light by recombination of electrons and holes within the layer without intentionally adding impurities; and a third semiconductor active layer that has a second conductivity type. The refractive index is smaller than the first one.
a fourth semiconductor cladding layer that has a second conductivity type and is transparent to the first light; a fifth semiconductor layer that has a second conductivity type and is transparent to the first light; a sixth semiconductor layer that is transparent to the first light and has a different refractive index from the fifth semiconductor, and has a thickness that is 1/4 of the wavelength of the first light.
The heterojunction bipolar optical transistor is formed by sequentially stacking a first light reflecting layer, which is formed by alternately stacking a plurality of pairs or more of fifth and sixth semiconductor layers of odd number multiples of .
a seventh semiconductor collector layer having a conductivity type and being transparent to the first and second lights; and a seventh semiconductor collector layer having a first conductivity type and absorbing to the first and second lights. an eighth semiconductor base layer having a second conductivity type and a first and second semiconductor base layer having a second conductivity type;
and a ninth semiconductor emitter layer that is transparent to the wavelength of light, and the first ohmic semiconductor layer and the emitter layer are provided with a metal electrode that applies a predetermined bias between them. A planar semiconductor optical switch characterized in that the heterojunction bipolar optical transistor is provided with an optical input window on the emitter side, and a laser output is obtained from a surface of the surface emitting laser opposite to the heterojunction bipolar optical transistor. 6. The planar semiconductor optical switch according to claim 5, wherein a reflective film for the first light made of a metal thin film is provided as an electrode on the first ohmic semiconductor layer. . 7. A laser output window is formed in the electrode formed on the first ohmic semiconductor layer, and a first dielectric material is formed on the first ohmic semiconductor layer in the laser output window. A first dielectric material and a second dielectric material having a different refractive index are alternately laminated in pairs such that each layer has a thickness of an odd multiple of 1/4 of the wavelength of the first light. 6. The planar semiconductor optical switch according to claim 5, further comprising a dielectric stack serving as a reflective layer for one light beam. 8. A surface-type semiconductor optical switch configured by sequentially stacking a surface-emitting laser and a heterojunction bipolar optical transistor formed on a predetermined substrate, wherein the surface-emitting laser conductivity type or the second opposite conductivity type
a conductivity type or a semi-insulating semiconductor substrate, and an impurity that gives the first conductivity type or a second conductivity type opposite thereto is not intentionally added or has the second conductivity type, and the first conductivity type is a first semiconductor layer that is transparent to light;
do not intentionally add impurities that give the conductivity type or a second conductivity type opposite to this, or have the second conductivity type,
and a second semiconductor layer that is transparent to the first light and has a refractive index different from that of the first semiconductor layer, each having a thickness that is an odd multiple of 1/4 of the wavelength of the first light. A first light reflective layer in which a plurality of pairs or more of certain first and second semiconductor layers are alternately laminated, and a third semiconductor having a first conductivity type and being transparent to the first light. and a fourth semiconductor cladding layer that also has the first conductivity type and is transparent to the first light, and an impurity that imparts the first or second conductivity type is not intentionally added. , a fifth semiconductor active layer that emits first light by recombination of electrons and holes, and a sixth semiconductor layer that has a second conductivity type and is transparent to the first light. , second
a seventh conductivity type and transparent to the first light;
an eighth semiconductor layer that has a second conductivity type, is transparent to the first light, and has a refractive index different from that of the seventh semiconductor layer, and each has a thickness of the seventh semiconductor layer. 1/ of the wavelength of 1 light
the heterojunction bipolar optical transistor has a second conductivity type; a ninth semiconductor collector layer that is transparent to the first and second lights; a ninth semiconductor collector layer that has a first conductivity type;
and a tenth semiconductor base layer that is absorbent to the second light; and an eleventh semiconductor emitter layer that has a second conductivity type and is transparent to the first and second lights. further comprising a metal electrode having a light input window on the eleventh semiconductor emitter layer via a mirror emitter layer, and another electrode on the third semiconductor layer. . A planar semiconductor optical switch, characterized in that a predetermined bias is applied between both electrodes, and a laser output is obtained from the side of the substrate surface opposite to the optical input window.