JPH09246669A - Semiconductor optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make the absorption spectrum of discrete light and the selectivity in the polarizing direction of light reflect in a semiconductor optical device to actuate the optical element by a method wherein the thickness of an upper barrier layer formed of a second semiconductor layer is formed specified times thicker than the lattice constant and a magnetic material thin film is provided on this barrier layer. SOLUTION: A semiconductor optical element having a light emission function is constituted into a structure, wherein an active layer of the optical element is formed of a quantum well layer 1, which consists of a first thin film-shaped semiconductor layer, and upper and lower barrier layers 2 and 3, which hold this semiconductor layer between them and respectively consist of second and third semiconductor layers having an energy forbidden band width wider than that of the first semiconductor layer, the thickness of the upper barrier layer 2 formed of the second semiconductor layer is formed 1 to 15 times thicker than the lattice constant and a magnetic material thin film 4 is provided on this layer 2. Thereby, the optical device, which operates while a magnetic field is applied to the active layer, can be realized without a device for applying the magnetic field to the active layer from the outside.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor optical device having a light emitting function for processing an optical signal, a light modulating function, an isolating function or a light detecting function.

[0002]

2. Description of the Related Art FIG. 2 shows a semiconductor optical device having a quantum well structure in an active layer such as a semiconductor laser, a light emitting diode, and a light modulation device, where 1 is a quantum film made of a thin film-shaped first semiconductor. Well layer, 2 is an upper barrier layer made of a second semiconductor formed on the quantum well layer 1, and 3 is a lower barrier made of a third semiconductor formed below the quantum well layer 1. Layers 5 and 5 are electrodes provided on the surfaces of the second and third barrier layers 2 and 3 for injecting a current I into the quantum well layer 1. In order to function as a light emitting device using this quantum well structure, it is necessary to generate electron-hole pairs in the quantum well layer 1. Here, it is assumed that injection of the current I produces electron-hole pairs. The electrons and holes generated in the quantum well layer cannot move in the direction perpendicular to the quantum well layer surface, but can freely move in the direction along the quantum well layer surface as shown in FIG. Therefore, the light absorption spectrum of the quantum well structure (the magnitude of the amount of light absorbed with respect to the energy of light) has a stepwise shape as shown in FIG. Usually, the energy of light emitted from a semiconductor laser or a light emitting diode is near the start of this staircase, as shown in FIG.

As shown in FIG. 5, a magnetic field B is vertically applied to the quantum well layer 1. Generally, the motion of valence particles in a magnetic field is called cyclotron motion. When the magnetic field B is applied to the quantum well layer 1 in the vertical direction as described above,
As shown in, the electrons and holes make circular motions in opposite directions with a radius determined by the magnetic field and the effective mass of each. Therefore, the movement range of electrons and holes is limited even in the plane of the quantum well layer, and the absorption spectrum of light becomes discrete from stepwise ones. This effect is called the Landau effect. Further, there is another effect that the absorption spectrum of light is changed by the application of a magnetic field, which is called Zeeman effect.

The Zeeman effect will be described with reference to FIG. Generally, electronic states of semiconductors are distinguished by four quantum numbers. Now, let this be n, 1, 1 _z , and s. n, 1,
1 _z takes various values, but s has only two kinds of -1/2 and 1/2. Usually, the electron energy is determined by n, 1, 1 _z , and does not change depending on the value of s. This is called energy degeneracy. Here, when a magnetic field is applied to the quantum well layer, the energy of electrons varies depending on the value of s, as shown in FIG. This phenomenon is called the Zeeman effect.
In conclusion, when a magnetic field is applied to the quantum well layer, the absorption spectrum of light becomes as shown in FIG. 7 due to the Landau effect and the Zeeman effect.

FIG. 7 is a diagram showing the absorption spectrum for linearly polarized light in the quantum well layer to which a magnetic field is applied, where L is the separation due to the Landau effect and s is the separation due to the Zeeman effect. From the absorption spectrum of this light, when a magnetic field is applied to the quantum well layer and used as a light emitting element, the energy of the light emitted from this light emitting element is limited to this discrete energy, so the current flowing through the light emitting element is It is easy to imagine that light with less monochromaticity can be obtained. Some reports have already been made (Y. Arakawa e
t.al Applied Physics Letters, 47, 1142 (1985)., K. Vaha
ra et.al, Applied Physics Letters, 50, 365 (1987)).

The value of s corresponds one-to-one with the rotation direction of circularly polarized light. Figure 7 shows the absorption spectrum for linearly polarized light in a quantum well layer to which a magnetic field is applied, but the absorption spectrum of light for a circularly polarized light in a quantum well layer to which a magnetic field is applied is As shown in 8,
The absorption energy of light can be selected depending on the polarization direction of light. However, it is limited to the case where the incident direction of light is parallel to the direction of the applied magnetic field.

[0007]

However, in order to apply a magnetic field to the quantum well layer made of the first semiconductor as described above, a large-scale device such as a superconducting magnet is required. Therefore, the effect of the magnetic field can be verified experimentally, but the actual application is impossible. An object of the present invention is to apply a magnetic field to an active layer of a semiconductor without using a large-scale device, and to perform a characteristic behavior of electrons and holes in the magnetic field, that is, a discrete absorption spectrum of light and light absorption. An object of the present invention is to provide a semiconductor optical device that operates by reflecting the selectivity with respect to the polarization direction.

[0008]

According to the present invention, as shown in FIG. 1, an active layer is a quantum well layer 1 made of a thin film-like first semiconductor, and a first quantum well layer 1 sandwiching the first semiconductor. In a semiconductor optical device having an emission function, which is formed of an upper barrier layer 2 and a lower barrier layer 3 made of second and third semiconductors having an energy band gap larger than that of the semiconductor, the second semiconductor is made of the second semiconductor. The thickness of the upper barrier layer 2 from 1 to 1 of the lattice constant
The semiconductor optical device is characterized in that the magnetic thin film 4 is formed on the barrier layer 2 on the upper side by 5 times.

Further, the active layer has a quantum well layer 1 made of a thin film of the first semiconductor, and second and third quantum well layers 1 having an energy band gap larger than that of the first semiconductor sandwiching the first semiconductor.
In the semiconductor optical device having an optical modulation function, which is formed of the upper barrier layer 2 and the lower barrier layer 3 made of the above semiconductor,
The upper barrier layer 2 made of the second semiconductor has a thickness of 1 to 15 times the lattice constant, and the magnetic thin film 4 is provided on the upper barrier layer 2. It is an optical element.

Further, the active layer has a quantum well layer 1 made of a thin film-shaped first semiconductor, and second and third quantum well layers 1 having a larger energy band gap than the first semiconductor sandwiching the first semiconductor.
In the semiconductor optical device formed of the upper barrier layer 2 made of the above semiconductor and the lower barrier layer 3 having the isolation function, the thickness of the upper barrier layer 2 made of the second semiconductor is set to the lattice constant. 1 to 15 times, and the magnetic thin film 4 is provided on the upper barrier layer 2 to provide a semiconductor optical device.

The active layer has a quantum well layer 1 made of a thin film of the first semiconductor, and second and third quantum well layers 1 sandwiching the first semiconductor and having an energy band gap larger than that of the first semiconductor.
In the semiconductor optical device having the photodetection function, which is formed from the upper barrier layer 2 and the lower barrier layer 3 made of the semiconductor of
The upper barrier layer 2 made of the second semiconductor has a thickness of 1 to 15 times the lattice constant, and the magnetic thin film 4 is provided on the upper barrier layer 2. It is an optical element.

Further, the barrier layer above the semiconductor element of the active layer is replaced with a superlattice structure in which at least one kind of semiconductor is composed of two or more kinds of semiconductors having an energy band gap larger than that of the first semiconductor, It is characterized in that the total thickness of the superlattice structure is 1 to 15 times the lattice constant.

[0013]

Embodiments of the present invention will be described below in detail. 1A is a structural diagram of a semiconductor optical device having a quantum well structure in an active layer of a semiconductor optical device such as a semiconductor laser or a light emitting diode of the present invention, and FIG. 1B is an energy band of the semiconductor optical device. Figure, 1
Is a quantum well layer made of a first semiconductor, 2 is an upper barrier layer made of a second semiconductor, and its thickness is 1 to 15 times the lattice constant. Reference numeral 3 is a lower barrier layer made of a third semiconductor, and 4 is a ferromagnetic thin film deposited on the upper barrier layer 2.

In the semiconductor optical device of the present invention, a magnetic field can be applied to the electrons and holes of the quantum well layer 1 forming the active layer of the semiconductor optical device as described below. First, coils 6 and 6 constituting an electromagnet as shown in FIG. 9A are arranged above and below in the drawing of the semiconductor optical device having the structure as shown in FIG. I
By applying a magnetic field B to the ferromagnetic thin film 4
Are magnetized in the direction perpendicular to the ferromagnetic thin film 4. Then, as shown in FIG. 9B, an upward magnetic field is generated around the ferromagnetic thin film 4. Reference numeral 7 is a magnetic moment generated by the magnetization.

However, in order to transmit the light emitted from the active layer of the semiconductor optical device, the thickness of the ferromagnetic thin film 4 is 1
It should be about 0 nm. With such a thickness, the magnetic field is reduced to 1/1000 or less just by separating from the ferromagnetic thin film 4 by about 0.1 μm. But,
As shown in FIG. 1, the upper barrier layer 2 that separates the ferromagnetic thin film 4 and the quantum well layer 1 is about 1 to 15 times the lattice constant and is very thin. In this case, the electrons and holes generated in the quantum well layer 1 are very close to the ferromagnetic thin film 4,
It is affected by the magnetic field generated from the ferromagnetic thin film 4.

Further, as shown in FIG. 1, since the barrier layer 2 above the quantum well layer 1 is very thin, the wave functions of electrons and holes generated in the quantum well layer 1 are in the ferromagnetic thin film 4. It's exuding. This means that the electronic state in the ferromagnetic thin film 4 affects the electronic state in the quantum well layer 1.
Electrons in the magnetized ferromagnetic thin film 4 have a force called exchange interaction with the surrounding electrons, and try to align the surrounding electrons and spins (small magnets attached to the electrons). Actually, the size of this exchange interaction determines the properties of the magnetic substance, but since we are considering a ferromagnetic substance, the exchange interaction is large. In the structure of the present invention, since the wave functions of electrons and holes generated in the quantum well layer 1 are exuded in the ferromagnetic thin film 4 as described above, the exchange interaction works. Therefore, considering the case shown in FIG. 9, the state of the upward spin with respect to the electrons in the quantum well layer 1 becomes energetically more stable. This has the same effect as the Zeeman effect.

That is, in the structure of the present invention, the electrons and holes generated in the quantum well layer 1 are doubly affected by the ferromagnetic thin film 4 due to the effect of the magnetic field and the exchange interaction. A semiconductor optical device capable of applying a magnetic field to the intended active layer can be realized. In order to make the operation of the semiconductor optical device of the present invention more effective, the thinner the barrier layer 2 on the upper side of the quantum well layer 1, the better. However, when the barrier layer 2 is thinned, it becomes more susceptible to the non-radiative recombination centers existing at the interface between the barrier layer 2 and the ferromagnetic thin film 4, and the electrons and holes generated in the quantum well layer 1 emit light. It disappears without doing. On the contrary, if the barrier layer 2 becomes thick, the magnitude of the magnetic field generated from the ferromagnetic thin film 4 and the exchange interaction become small, and it becomes impossible to achieve the object of the present invention.

The magnetization direction of the ferromagnetic thin film 4 is preferably perpendicular to the ferromagnetic thin film 4. When magnetized parallel to the ferromagnetic thin film 4, both Landau effect and Zeeman effect are reduced. However, the optical signal processing element reflecting the properties of electrons and holes of the quantum well layer 1 to which a magnetic field is applied, which is the object of the present invention, can be realized although the effect of the magnetic field is weakened. Further, when magnetized in the horizontal direction with respect to the ferromagnetic thin film 4, it becomes possible to realize selection of the absorbed energy of the light with respect to the polarization direction of the light incident in parallel with the ferromagnetic thin film 4.

[0019]

【Example】

(Embodiment 1) FIG. 10 is a diagram showing Embodiment 1 of the present invention. As shown in FIG. 10A, first, GaAs (1
00) The GaAs buffer layer 9 and the superlattice buffer layer 10 are sequentially grown on the non-doped substrate 8 by a method such as a molecular layer epitaxy method and a metal organic chemical vapor deposition method. next,
To form a quantum well structure, AlGaAs, which is a lower barrier layer 3 made of a third semiconductor, is grown to 50 nm, and then GaAs, which is a quantum well layer 1 made of the first semiconductor, is grown.
Is grown to 10 nm. The upper barrier layer 2'grows two cycles of at least two kinds of semiconductors, for example, AlAs and GaAs each having two atomic layers, in which at least one kind of semiconductor has an energy band gap larger than that of the quantum well layer 1 made of the first semiconductor. To form a superlattice structure. The upper barrier layer 2 '
The thickness of the quantum well layer 1 is about 2 nm for 8 atomic layers.
The wave function of reaches the surface easily. Put the material formed in this way into a well-known sputtering device (not shown),
As shown in FIG. 10B, a Co—Cr ferromagnetic thin film 4 is deposited to a thickness of 10 nm on the upper barrier layer 2 ′.

In order to magnetize the ferromagnetic thin film 4,
The material formed as shown in FIG. 10B is put between the coils 6 and 6 serving as electromagnets as shown in FIG. 9A and magnetized. The magnetization direction is perpendicular to the surface of the ferromagnetic thin film 4. The saturation magnetization of this ferromagnetic thin film 4 is C
Since it is almost the same as o and becomes 1.8 T, a maximum magnetic field of 1.8 T is applied to the electrons and holes in the quantum well layer 1, and the upper barrier layer 2'is exchanged because it is very thin. Interaction works effectively. As shown in FIG. 11, this semiconductor optical device functions as a semiconductor optical device in which electrons and holes excited by light (laser light) 11 are recombined to spontaneously emit light 12. The semiconductor optical device manufactured in this manner showed higher luminous efficiency than the conventional one. Although Co—Cr is used as the ferromagnetic thin film 4 in this embodiment, another metal magnetic material, a magnetic organic thin film, or a magnetic semiconductor may be used.

(Second Embodiment) FIG. 12 is a view showing a second embodiment of the present invention. In FIG. 12A, 8 is Ga
As non-doped substrate, 9 GaAs buffer layer, 10 superlattice buffer layer, 3 GaAs lower barrier layer, 1 InGaAs quantum well layer, 2 GaAs upper barrier layer, and its thickness is 6 nm. Is. 4 is a ferromagnetic thin film similar to the above. In this embodiment also, as shown in FIG. 12B, the semiconductor optical device functions as the electrons and holes excited by the light (laser light) 11 are recombined to spontaneously emit the light 12. The semiconductor optical device manufactured in this manner showed higher luminous efficiency than the conventional one.

(Third Embodiment) FIG. 13 is a diagram showing a third embodiment of the present invention. Fig. (A) is a view showing materials of a light emitting diode having a pn junction manufactured by a molecular layer epitaxy method, a metal organic chemical vapor deposition method, etc., 13 is an n-type GaAs substrate, and 14 is an n-type GaAs buffer layer. , 15 is an n-type superlattice buffer layer, 16 is an n-type AlGaAs layer, and 3 is A
1GaAs is a lower barrier layer, 1 is a GaAs quantum well layer, 2'is an upper barrier layer similar to that of the first embodiment, and 17 is a p-type AlGaAs layer.

Next, as shown in FIG. 3B, Au- is formed on the back surface of the material formed as described above by using a vacuum evaporation apparatus.
The electrode 18 is formed by evaporating a Ge—Ni alloy. Next, as shown in FIG. 6C, an ultraviolet exposure device (not shown) and an organic resist 19 (for example, AZ1400-17).
A slit 19a having a pattern as shown in the drawing is formed in the organic resist 19 by using. (C ') is a top view of the material. Next, as shown in FIG. 3D, an Au—Zn—Ni alloy is vapor-deposited on the slits 19 a formed in the organic resist 19 by using a vacuum vapor deposition device (not shown) to form the organic resist 19. If removed with acetone, the electrode 20 for forming an electric current is formed. (D ') is a top view of the material. Next, as shown in FIG. 7E, the electrode 20 is masked using an ultraviolet exposure device and an organic resist 19 and is formed on the organic resist 19 in which holes 19b having a fine pattern of 10 μm × 10 μm are opened. To do.
(E ') is a top view of the material.

Next, as shown in FIG. 14 (a), the material formed as shown in FIG. 13 (e) is treated with sulfuric acid / hydrogen peroxide water / water at a volume ratio of 4: 1. Then, the p-type AlGaAs layer 17 is etched to the upper side of the active layer through the fine pattern of holes 19b. Next, as shown in FIG. 7B, a Co—Cr ferromagnetic thin film 4 is deposited to a thickness of 10 nm on the etched slit using a sputtering device (not shown). Next, as shown in FIG. 7C, the semiconductor optical device obtained by removing the organic resist 19 with acetone is put between the coils serving as the electromagnets and magnetized as described in the first embodiment. . By the method described above, a light emitting diode in which a magnetic field is applied to the active layer by current injection can be manufactured. Then, as shown in FIG. 3D, when a current I is passed through the electrodes 18 and 20 of the light emitting diode, the Co--Cr
Light 12 is emitted from the ferromagnetic thin film 4. The light emitting diode described above is manufactured by forming a large number of light emitting diodes on a wafer as described above and finally cutting out the individual light emitting diodes. The manufactured semiconductor optical device showed higher luminous efficiency (ratio of injection current and luminous intensity) than the conventional one. In the above description, the active layer is the same as that shown in Example 1, but it may be replaced with the one shown in Example 2.

(Fourth Embodiment) FIG. 15 is a view showing a fourth embodiment of the present invention. (A) is a perspective view of a material of a semiconductor laser having a pn junction manufactured by the same manufacturing procedure (method) as in Example 3, where 21 is an Au-Ge-Ni electrode and 22 is an n-type. GaAs substrate, 23 is n-type AlGa
As layer, 3 is a barrier layer below AlGaAs, and 1 is GaA.
s quantum well layer, 2'is an upper barrier layer similar to that of the first embodiment, 24 is a p-type AlGaAs layer, and 25 is a p-type GaA.
s layer, 26 is a SiN thin film attached for current constriction,
27 and 27 are Au-Zn-Ni electrodes. next,
(B) As shown in the figure, the p-type GaAs layer 25 and the p-type AlGaAs layer 24 are formed as active layers between the electrodes 27, 27 of the material by the same manufacturing procedure (method) as in the third embodiment. Of the Co—Cr ferromagnetic thin film 4 attached to the above-mentioned etched slits, a semiconductor laser to which a magnetic field is applied by current injection can be manufactured. The produced semiconductor laser exhibited a lower oscillation threshold than the conventional one, and the fluctuation of the wavelength of the emitted laser light was suppressed to a low level. Further, when the magnetization direction is parallel to the ferromagnetic thin film, it is possible to realize a semiconductor laser that oscillates with circularly polarized light. It is also possible to switch the polarization direction of the laser light by reversing the magnetization direction. (B) As shown in the figure, when a current I is passed through the manufactured semiconductor lasers through the electrodes 21 and 27,
Laser light 28 is emitted from the active layer including the quantum well layer 1.

(Fifth Embodiment) FIG. 16 is a view showing a fifth embodiment of the present invention. In this embodiment, the material produced in the above-mentioned Embodiment 3 (see FIG. 14 (d)) is used as an optical modulator. In this case, differently from the case of using as a light emitting diode, a DC power supply 29 for applying a reverse bias and a modulator 30 for performing optical modulation are connected between the electrodes 18 and 20 of the optical modulation element. Then, light (laser light) is passed through the focusing lens 31 in parallel with the active layer including the quantum well layer 1.
When 32 is made incident, the light (laser light) 32 ′ modulated by the modulator 30 is emitted through the focusing lens 31.

FIG. 17 shows a light absorption spectrum showing the operating principle of the light modulation element of the fifth embodiment. Since the absorption spectrum of this light changes due to the quantum confined Stark effect, a dispersion-type or absorption-type optical modulator can be manufactured depending on the wavelength of the optical signal. When the magnetization direction is parallel to the ferromagnetic thin film, the absorption wavelength of light differs depending on the polarization direction as shown in FIG. Further, as shown in FIG. 19, it is possible to modulate the polarization direction in correspondence with the signal.

(Sixth Embodiment) FIG. 20 is a view showing a sixth embodiment of the semiconductor optical device of the present invention. In this embodiment, the third embodiment
The material (see (d) of FIG. 14) prepared in step 1 is used as an optical isolator. In this figure, 29 is a DC power supply for applying a reverse bias to the material (element), 3
Reference numerals 1 and 31 are focusing lenses, 33 is a λ / 4 plate (converts circularly polarized light and linearly polarized light), 32 is incident light (laser light), and 32 'is emitted light (laser light).

20A shows an arrangement in which the magnetization direction is perpendicular to the ferromagnetic thin film, and FIG. 20B shows an arrangement in which the magnetization direction is parallel to the ferromagnetic thin film. As described in the description of the prior art, the quantum well layer to which a magnetic field is applied has a different light absorption wavelength depending on the rotation direction of circularly polarized light. However, the incident direction of light (laser light) needs to be parallel to the direction of the magnetic field. FIG. 21 is a diagram for explaining the operation of the semiconductor optical device of the sixth embodiment. First, as described in the description of the prior art, the semiconductor optical device of the present invention can absorb counterclockwise circularly polarized light by appropriately selecting the direction of the magnetic field and the wavelength of light. When linearly polarized light (laser light) enters from the left, the semiconductor optical element absorbs counterclockwise light (laser light), so the light emitted from the semiconductor optical element (laser light) is clockwise. Become. This light (laser light)
Is passed through a λ / 4 plate (converts circularly polarized light and linearly polarized light) 33 to return to the original linearly polarized light. Conversely, when linearly polarized light (laser light) enters from the right side, it becomes counterclockwise light due to the λ / 4 plate 33, which is absorbed by the semiconductor optical element and does not propagate to the right side. . In this way, it functions as an optical isolator.

(Embodiment 7) FIG. 22 is a diagram showing Embodiment 7 of the semiconductor optical device of the present invention. In this example, the material prepared in Example 3 (see (d) of FIG. 14) is used as a photodetector. In this figure, 31 is a focusing lens, 32 is incident light (laser light), 29 is a DC power supply for applying a reverse bias to the semiconductor optical device, and 34 is light (laser light) absorbed by the semiconductor optical device. It is a detection resistor for detecting a current when a current flows through the bias circuit as a voltage. In the case of this embodiment, unlike the case where the semiconductor optical device is used as a light emitting diode, a reverse bias is applied to the semiconductor optical device. FIG. 23 shows an energy band diagram of this semiconductor optical device. However, it is an energy band diagram of the electrode region, not the ferromagnetic thin film. When light (laser light) having an energy larger than the energy gap enters, a current flows through the circuit and a voltage is generated in the detection resistor 34.

[0031]

As described above, according to the present invention, the active layer has the thin film-shaped first semiconductor and the second and the second semiconductors which sandwich the first semiconductor and have an energy band gap larger than that of the first semiconductor. A semiconductor optical element having a light emitting function, a semiconductor optical element having a light modulation function, a semiconductor optical element having an isolation function, and a semiconductor optical element having a light detecting function, wherein the semiconductor element of the active layer is Since the thickness of the second semiconductor on the front surface side is set to 1 to 15 times the lattice constant and the magnetic thin film is provided on the second semiconductor, a semiconductor optical element is formed, so that the active layer can be provided without an external magnetic field applying device. It is possible to realize a semiconductor optical device that operates while a magnetic field is applied to the device. Further, the barrier layer above the semiconductor element of the active layer is replaced with a superlattice structure in which at least one kind of semiconductor is composed of two or more kinds of semiconductors having an energy band gap larger than that of the first semiconductor, Since the semiconductor optical device has a total thickness of the lattice structure which is 1 to 15 times the lattice constant, a semiconductor optical device that operates while the magnetic field is applied to the active layer can be realized without a device for applying a magnetic field from the outside.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a semiconductor optical device of the present invention.

FIG. 2 is a diagram illustrating a conventional technique.

FIG. 3 is a diagram showing how electrons and holes move in a quantum well layer.

FIG. 4 is a diagram showing a light absorption spectrum of a quantum well layer.

FIG. 5 is a diagram showing how electrons and holes move when a magnetic field is applied to the quantum well layer.

FIG. 6 is a diagram illustrating the Zeeman effect.

FIG. 7 is a diagram showing an absorption spectrum for linearly polarized light in a quantum well layer to which a magnetic field is applied.

FIG. 8 is a diagram showing an absorption spectrum for circularly polarized light of a quantum well layer to which a magnetic field is applied.

FIG. 9 is an explanatory diagram of a semiconductor optical device of the present invention.

FIG. 10 is an explanatory diagram of Embodiment 1 of the semiconductor optical device of the present invention.

FIG. 11 is a diagram showing an operation of Example 1 of the semiconductor optical device of the present invention.

FIG. 12 is an explanatory diagram of Embodiment 2 of the semiconductor optical device of the present invention.

FIG. 13 is an explanatory diagram of the manufacturing process of Example 3 of the semiconductor optical device of the present invention.

FIG. 14 is an explanatory diagram of the manufacturing process of Example 3 of the semiconductor optical device of the present invention.

FIG. 15 is an explanatory diagram of Embodiment 4 of the semiconductor optical device of the present invention.

FIG. 16 is a perspective view illustrating a fifth embodiment of the semiconductor optical device of the present invention.

FIG. 17 is a diagram showing a light absorption spectrum showing the operating principle of Example 5 of the semiconductor optical device of the present invention.

FIG. 18 is a diagram showing a light absorption spectrum showing the operating principle when the magnetization direction is made parallel to the ferromagnetic thin film in Example 5 of the semiconductor optical device of the present invention.

FIG. 19 is a diagram showing a modulation operation when the magnetization direction is made parallel to the ferromagnetic thin film in Example 5 of the semiconductor optical device of the present invention.

FIG. 20 is a perspective view illustrating a sixth embodiment of the semiconductor optical device of the present invention.

FIG. 21 is a diagram showing the operation of Example 6 of the semiconductor optical device of the present invention.

FIG. 22 is a perspective view illustrating a seventh embodiment of the semiconductor optical device of the present invention.

FIG. 23 is a diagram showing the operation of Example 7 of the semiconductor optical device of the present invention.

[Explanation of symbols]

 1 quantum well layer 2, 2'upper barrier layer 3 lower barrier layer 4 ferromagnetic thin film 5 electrode 6 coil 7 magnetic moment 8 GaAs non-doped substrate 9 GaAs buffer layer 10 superlattice buffer layer 11 incident light 12 emission Light 13 n-type GaAs substrate 14 n-type buffer layer 15 n-type superlattice buffer layer 16 n-type AlGaAs layer 17 p-type AlGaAs layer 18 electrode 19 organic resist 19a slit 19b fine pattern hole 20 electrode 21 Electrode 22 n-type GaAs substrate 23 n-type AlGaAs layer 24 p-type AlGaAs layer 25 p-type GaAs layer 26 SiN thin film 27 electrode 28 laser light 29 DC power supply 30 modulator 31 focusing lens 32 incident light 32 'emission Light (laser light) 33 λ / 4 plate 34 Detection resistor

Claims (5)

[Claims] 1. An active layer is composed of a quantum well layer made of a thin film-shaped first semiconductor and second and third semiconductors sandwiching the first semiconductor and having an energy band gap larger than that of the first semiconductor. In a semiconductor optical device having a light emitting function, which is formed of the upper barrier layer and the lower barrier layer, the thickness of the upper barrier layer made of the second semiconductor is set to a lattice constant of 1 to 15
A semiconductor optical device characterized in that a magnetic thin film is provided on the upper barrier layer. 2. An active layer comprising a quantum well layer made of a thin film-shaped first semiconductor, and second and third semiconductors sandwiching the first semiconductor and having an energy band gap larger than that of the first semiconductor. In the semiconductor optical device having an optical modulation function, which is formed of the upper barrier layer and the lower barrier layer, the thickness of the upper barrier layer made of the second semiconductor is set to 1 to 1 of the lattice constant.
A semiconductor optical device characterized in that it is made 5 times larger and a magnetic thin film is provided on the upper barrier layer. 3. An active layer comprising a quantum well layer made of a thin-film first semiconductor, and second and third semiconductors sandwiching the first semiconductor and having an energy band gap larger than that of the first semiconductor. In a semiconductor optical device having an isolation function, which is formed of an upper barrier layer and a lower barrier layer, the thickness of the upper barrier layer made of the second semiconductor is set to 1 of a lattice constant.
The semiconductor optical device is characterized in that the magnetic thin film is provided on the upper barrier layer. 4. An active layer comprising a quantum well layer made of a thin film-shaped first semiconductor, and second and third semiconductors sandwiching the first semiconductor and having an energy band gap larger than that of the first semiconductor. In a semiconductor optical device having a photodetection function, which is formed of an upper barrier layer and a lower barrier layer, the thickness of the upper barrier layer made of the second semiconductor is set to a lattice constant of 1 to 1
A semiconductor optical device characterized in that it is made 5 times larger and a magnetic thin film is provided on the upper barrier layer. 5. The barrier layer on the upper side of the semiconductor device of the active layer according to claim 1, wherein at least one kind of semiconductor has two or more kinds having an energy band gap larger than that of the first semiconductor. A semiconductor optical device characterized in that it is replaced with a superlattice structure composed of a semiconductor, and the total thickness of the superlattice structure is set to 1 to 15 times the lattice constant.