Abstract: An optical device comprises a substrate, a light-emitting portion, and a plurality of light-receiving portions, the light-emitting portion and a plurality of light-receiving portions being closely laminated on the same substrate, wherein returned light obtained after light emitted from a resonator end face of the light-emitting portion has been reflected on an irradiated portion is received and detected near a confocal point by a plurality of light-receiving portions. In this optical device such as an optical pickup, the number of optical ssemblies can be reduced, an alignment for disposing optical assemblies can be simplified, the whole of the optical device can be simplified and miniaturized, and a stable tracking servo can be effected by effectively utilizing advantages of a push-pull method.

Abstract: There is provided an optical semiconductor device, including a first semiconductor layer, a first insulating layer formed on the first semiconductor layer, the first insulating layer having a different index of refraction from that of the first semiconductor layer, a highly doped, second semiconductor layer formed on the first insulating layer, a third semiconductor layer formed on the second semiconductor layer, a device isolation region having a depth starting at an upper surface of the third semiconductor layer and terminating at an upper surface of the first insulating layer, the device isolation region defining a device formation region therein, the device formation region being formed with a recess starting at an upper surface of the third semiconductor layer and terminating at an upper surface of the second semiconductor layer, a second insulating layer covering an inner sidewall of the recess therewith, a multi-layered structure formed within the recess, the multi-layered structure having at least a q

Abstract: After the active layer including indium is formed, the evaporation preventing layer is formed at a temperature which does not cause liberation of indium. The p-type Al.sub.x Ga.sub.1-x N (0.ltoreq.X.ltoreq.1) or the like is used for the evaporation preventing layer. Increasing the substrate temperature to as high as 1020.degree. C. for forming the upper cladding layer does not cause liberation of indium from the active layer because the evaporation preventing layer is provided. As a result, the composition ratio of indium can be easily controlled and the high-quality active layer and the high-quality interface between the active layer and the upper cladding layer can be provided.

Abstract: In the structure of the device of the invention, a supper-lattice buffer layer is formed between the undoped layer and doped layers. This super-lattice buffer layer serves as a carrier-piling up layer in place of the undoped layer in the conventional device. Thus, the amounts of the piled-up carriers in the undoped layer can be greatly reduced and hence no band filling effect occurs in the undoped layer. Consequently, an optical device having a flat frequency characteristic can be produced without losing its modulating characteristic.

Abstract: A semiconductor memory device in which a stored information can be simply erased only by an electric signal so as to be rewritten is provided. The semiconductor memory device includes: (a) a semiconductor chip having an array of memory cells, stored information in the memory cells being erasable by light irradiation; (b) a light emitting element irradiating a light into the memory cells portion of the semiconductor chip; and (c) a package in which the semiconductor chip and the light emitting element are encapsulated with a resin in one body.

Abstract: A light control substance having a negative input-output characteristic is used to invert optical signals. The light control substance is an absorbing substance and has a multi-level energy structure such that ground state absorption occurs between a ground level and a level higher than the ground level and excited state absorption occurs between an excited level and a level higher than the excited level. At a specific wavelength, a variation .DELTA.Iout in the intensity of output light and a variation .DELTA.Iin in the intensity of input light satisfy the following equations:.DELTA.Iout=?1-.alpha..sub.1 (1+.alpha..sub.2 .gamma.)!.DELTA.Iin (1).alpha..sub.1 (1+.alpha..sub.2 .gamma.)>1 (2)where .alpha..sub.1 is an absorbance of the ground state absorption, .alpha..sub.2 is an absorbance of the excited state absorption, and .gamma. is a ratio of electrons relaxing from the level higher than the ground level to the exited level. As a result, the value of .DELTA.Iout/.DELTA.Iin becomes negative.

Abstract: A nonlinear optical transistor comprises a pair of surface emitting semiconductor laser diodes, a phase modulator including a waveguide confined by a pair of first mirrors in the horizontal direction and located between the pair of surface emitting semiconductor laser diodes and a multiplicity of electrodes for controlling these elements. The transistor is characterized by its input optical signals for controlling the system; its high sensitivity; its capability to generate narrow, circularly symmetrical and single mode output signals; and its ability to carry out a multi-level processing of optical signals as well as computing operations and storage functions. These characteristics are obtained by introducing a pair of Fabry-Perot microresonators, each of the Fabry-Perot microresonators having a vertical optical axis, by utilizing a plurality of multilayer Bragg reflectors, wherein surface coatings are applied to the input faces to increase the reflection index to 1.

Abstract: A method of manufacturing a light converter with an LED and an amorphous-silicon pin heterojunction diode includes steps of a) preparing an LED structure on one side of a substrate as a light-emitting unit; b) forming a buffer layer on the other side of the substrate; and c) depositing a pin (positive type/intrinsic type/negative type) diode on the buffer layer as a light-absorbing unit this blue/red light converter, and the value of rise time obtained under 1 k.OMEGA. is 112.5 .mu.sec. The present invention desirably lower the cost, simplify the preparation process, and avoids degrading features of a light converting unit by over-heating during the process of preparing the pin diode.

Abstract: In an optoelectronic integrated device having an optical element section in the wavelength region of 1.33 to 1.55 .mu.m and an electronic element section such as an HEMT integrated in a monolithic form on a GaAs substrate, the optical element section includes light receiving elements or light emitting elements, and an optical absorption layer of the light receiving element or a semiconductor layer forming an active layer of the light emitting element is formed of GaAsN-series compound semiconductor which is lattice-matching with the GaAs substrate, particularly, one of GaAsN, InGaAsN, InGaAsPN, GaAlAsN, InGalAsN, AlGaAsPN and InGaAlAsPN.

Abstract: An optically controlled light modulator device, consisting of a semiconductor heterostructure with at least one quantum well layer and two strained barrier layers. The device is capable of modulating a first beam ("read" beam), through the Quantum Confined Stark Effect and the influence of a perpendicular electric field, produced all-optically by electrons and holes which are generated by the absorption, either of the first beam itself or of a second beam ("control" beam), and which are separated in opposite directions by the piezoelectric field of the barrier layers.

Abstract: The optoelectronic integrated device includes a semiconductor substrate, a vertical-cavity surface-emitting semiconductor laser formed on the semiconductor substrate, a phototransistor stacked over the vertical-cavity surface emitting semiconductor laser, for driving the vertical-cavity surface-emitting semiconductor laser, and a semiconductor buffer structure interposed between the vertical-cavity surface-emitting semiconductor laser and the phototransistor. The vertical-cavity surface-emitting semiconductor laser includes: a bottom semiconductor mirror; a top semiconductor mirror; and an active region interposed between the bottom semiconductor mirror and the top semiconductor mirror and having a strained quantum well structure for emitting light having a wavelength of .lambda.. The phototransistor includes: a collector layer; an emitter layer; and a base layer interposed between the collector layer and the emitter layer and absorbing light having a wavelength of .lambda..

Abstract: An optical functional semiconductor element which performs ultrafast, high-contrast logic operation through utilization of the high speed of light velocity. A resonant-tunneling diode having a negative resistance characteristic is provided apart from a light absorbing layer formed by one of i-type layers of what is called a triangular barrier diode of an nipin or pinip structure, by which as the quantity of incident light increases, the quantity of transmitted current is switched from increase to decrease, the amount of change is made high-contrast and an ultrafast logic operation can be performed.

Abstract: A semiconductor light emitting diode includes a compound semiconductor substrate and a double-hetero structure of (Al.sub.x Ga.sub.1-x).sub.y In.sub.1-y P (0.ltoreq.x.ltoreq.1, 0<y<1) as an active layer, and an upper clad layer of the double-hetero structure has a larger band gap energy (Eg) than the band gap energy of the active layer and has a thickness of 3-50 .mu.m.

Abstract: Novel optical modulators and other high performance Faraday-Stark magneto-optoelectronic devices (MOE's) are disclosed that allow electrical adjusting of the polarization (or other optical properties) of an excitation light at high modulation bandwidth and deep modulation depths through the Faraday-Stark effect. The high performance Faraday-Stark magneto-optoelectronic devices of the present invention include a Faraday-Stark cell having at least one quantum well formed in a semiconductor or other material defining transition energies and wavefunction overlaps that correspond to the presence and/or magnitude of magnetic and electric fields that may be present to the quantum wells of the cell.

Abstract: There is provided a monolithic photocoupler which is easy to integrate. An SOI structure is formed by providing a first insulation layer on a silicon substrate. The semiconductor single crystal region is further divided by trench insulation layers into separate regions. Light emitting elements are formed on one of the separated semiconductor single crystal region and light receiving elements are formed on the other semiconductor single crystal region. The light emitting elements are obtained by forming light emitting diodes made of GaAs or the like on the substrate using a heterogeneous growth process. An optical waveguide made of a material which is optically transparent and electrically insulative such as a TiO.sub.2 film on each pair of light emitting and light receiving elements. The insulation layers constituted by SiO.sub.2 layers have a refractive index smaller that of the active layer of the substrate.

Abstract: Optoelectronic devices such as photodetectors, modulators and lasers with improved optical properties are provided with an atomically smooth transition between the buried conductive layer and quantum-well-diode-containing intrinsic region of a p-i-n structure. The buried conductive layer is grown on an underlying substrate utilizing a surfactant-assisted growth technique. The dopant and dopant concentration are selected, as a function of the thickness of the conductive layer to be formed, so that a surface impurity concentration of from 0.1 to 1 monolayer of dopant atoms is provided. The presence of the impurities promotes atomic ordering at the interface between the conductive layer and the intrinsic region, and subsequently results in sharp barriers between the alternating layers comprising the quantum-well-diodes of the intrinsic layer.

Abstract: A semiconductor laser device includes a semiconductor laser having a pair of facets and disposed on a semiconductor substrate and a photodiode having a light responsive surface on which a laser beam emitted from one of the facets of the semiconductor laser is incident, also disposed on the semiconductor substrate. The pair of facets of the semiconductor laser and the light responsive surface of the photodiode are both perpendicular to the surface of the semiconductor substrate, and the light responsive surface of the photodiode is disposed so that light of the laser beam reflected by the light responsive surface does not return to the emitting point of the laser beam. Therefore, return light noise generated in the semiconductor laser is avoided. In addition, the pair of facets of the semiconductor laser and the light responsive surface of the photodiode can be formed simultaneously by dry etching, thereby shortening the fabricating process.

Abstract: A semiconductor device having superior light output efficiency is disclosed. A p-Si diffusion layer is formed on a Si substrate and an n-Si diffusion layer is formed in the p-Si diffusion layer. An n-GaAs layer constituting an active region for emitting light is grown on the p-Si diffusion layer and the n-Si diffusion layer of the Si substrate and a p-GaAs layer constituting an active region for emitting light is grown on the n-GaAs layer. An upper electrode is disposed on an upper surface of the p-GaAs layer above the p-Si diffusion layer. Current is injected from the upper electrode through a region of the pn junction between the n-GaAs layer and the p-GaAs layer other than that directly below the upper electrode, and light is emitted from this region. The emitted light passes through the p-GaAs layer to outside the device without passing through and being attenuated by the upper electrode.

Abstract: An optical device for detecting a magneto-optical signal can be simplified and miniaturized in arrangement. An optical device for detecting a magneto-optical signal includes an optical element (101) in which a light-emitting portion (4) and a light-receiving portion (5) are closely disposed on a common substrate and in which reflected-back light obtained from a magneto-optical medium (34) after light emitted from the light-emitting portion (4) was reflected on the magneto-optical medium (34) is detected at a position near confocal position by the light-receiving portion (5). The light-receiving portion (5) on the optical element (1) has a light-receiving surface inclined relative to the optical axis of the reflected-back light formed thereon so that the light-receiving portion has a polarization selective transmittance function on its surface. Thus, the reflected-back light from the magneto-optical medium (34) can be received and detected by the light-receiving portion (5) on the optical element (101).

Abstract: Novel semiconductor devices are monolithically defined with p-type and n-type wide bandgap material formed by impurity induced layer disordering of selected regions of multiple semiconductor layers. The devices are beneficially fabricated by simultaneously forming the n-type and p-type layer disordered regions with sufficiently abrupt transitions from disordered to as-grown material. The novel devices include a heterojunction bipolar transistor monolithically integrated with an edge emitting heterostructure laser or a surface emitting laser, a heterostructure surface emitting laser, a heterostructure surface emitting laser having active distributed feedback, devices containing multiple buried layers which are individually contacted such as p-n junction surface emitting lasers, carrier channeling devices, and "n-i-p-i" or hetero "n-i-p-i" devices, and novel interdigitated structures, such as optical detectors and distributed feedback lasers.

Abstract: Photodiodes are integrally formed with vertical cavity surface emitting lasers (VCSELs) and superluminescent light emitting diodes (SLEDs) for monitoring optical radiation intensities. In different embodiments, the photodiode is epitaxially formed within a mirror of a VCSEL, non-epitaxially formed on top of a VCSEL, non-epitaxially formed on side of a VCSEL, or formed on the substrate on the side opposite the VCSEL. A lateral injection vertical cavity surface emitting laser is also disclosed for integration with a lateral PIN photodiode. A photodiode having the same epitaxial layers as a VCSEL is also integrally formed alongside of the VCSEL. Similar devices using SLEDs are also disclosed.

Abstract: A nitride semiconductor device is made using a molecular beam epitaxy growth apparatus having a gas source for supplying a compound including gaseous nitrogen, solid body sources for supplying Group III constituents, and sources for supplying n-type and p-type dopants. A gaseous state compound containing nitrogen, and a Group III constituent is supplied to the surface of a substrate, wherein the substrate is at a temperature of 300.degree. to 1000.degree. C. and is under a pressure of less than 10.sup.-5 Torr, to produce a first layer of oriented polycrystalline nitride semiconductor on the substrate at a growth rate of 0.1 to 20 Angstroms/second. Subsequently, a gaseous state compound containing nitrogen and a Group III constituent is supplied to the surface of the first layer of the substrate to produce a single crystal nitride semiconductor layer on the first layer at a growth rate of 0.1 to 10 Angstroms/second.

Abstract: Photodiodes are integrally formed with vertical cavity surface emitting lasers (VCSELs) and superluminescent light emitting diodes (SLEDs) for monitoring optical radiation intensities. In different embodiments, the photodiode is epitaxially formed within a mirror of a VCSEL, non-epitaxially formed on top of a VCSEL, non-epitaxially formed on side of a VCSEL, or formed on the substrate on the side opposite the VCSEL. A lateral injection vertical cavity surface emitting laser is also disclosed for integration with a lateral PIN photodiode. A photodiode having the same epitaxial layers as a VCSEL is also integrally formed alongside of the VCSEL. Similar devices using SLEDs are also disclosed.

Abstract: A superluminescent diode includes a semiconductor substrate of a first conductivity type. A lower cladding layer of the first conductivity type is provided on the semiconductor substrate. An active layer is provided on the lower cladding layer. An upper cladding layer of a second conductivity type opposite to the first conductivity type is provided on the active layer. A current blocking layer of the first conductivity type is buried in the upper cladding layer. The current blocking layer has a stripe-shaped groove serving as a current-injection region. The current-injection region is formed in a manner that it extends from an end face of a chip to the inside of the chip, and has a length shorter than that of the chip. The current blocking layer is made of a material having a band gap energy not greater than that of the active layer and a refractive index not smaller than that of the active layer so that light advancing in the active layer is absorbable.

Abstract: A light emitting diode (LED) and resistors for varying the light intensity of the LED are formed on a single chip. Each of the LED portion and the resistor portion includes an active layer and a clad layer successively deposited on a substrate of the chip. The substrate may be doped with one of P-type dopant and N-type dopant and the clad layer with the other of P and Y-type dopants. A first and second electrodes are formed on an exposed surface of the substrate and the clad layer of the LED portion respectively. A plurality of resistor electrodes are formed on the clad layer of the resistor portion. It is preferable to have different spacing between the resistor electrodes to form variable resistances.

Abstract: A semiconductor optical monolithic integration device comprises a semiconductor substrate including an active region and a passive region. Epitaxial layers including a multiple quantum well structure have a variation in band gap energy and thickness along a waveguide direction. The epitaxial layers in the active region are selectively grown by a metal organic vapor phase epitaxy on a first selective growth area defined by a first mask pattern provided in the active region except in the passive region. The first mask pattern has a variation in width along the waveguide direction. The epitaxial layers are simultaneously and non-selectively grown on the entirety of the passive region by metal organic vapor phase epitaxy and epitaxial layers having a mesa structure in the active region and a plane structure in the passive region are formed.

Abstract: By i) forming a layered structure of an undoped single crystalline Si layer and single crystalline Si.sub.0.8 Ge.sub.0.2 mixed crystal layer on an n-Si(100) substrate, a second undoped single crystalline Si layer on it, and a p type hydrogenated amorphous Si.sub.1-B C.sub.B layer on it, iii) mounting an n-Si.sub.0.55 Ge.sub.0.40 C.sub.0.05 layer on an n-Si(100) substrate and forming a layered structure of an undoped single crystalline Si.sub.0.55 Ge.sub.0.40 C.sub.0.05 layer and Si.sub.0.8 Ge.sub.0.2 layer, an undoped single crystalline Si.sub.0.55 Ge.sub.0.40 C.sub.0.05 layer, and a p-Si.sub.0.55 Ge.sub.0.40 C.sub.0.05 layer sequentially on it or iv) mounting an n type single crystalline Si layer on an n-Si(100) substrate and forming a layered structure of an undoped single crystalline Si layer and Si.sub.0.8 Ge.sub.0.1 Sn.sub.0.1 layer, an undoped single crystalline Si layer, and a p type single crystalline Si layer sequentially on it, a semiconductor optical device is obtained.

Abstract: In a semiconductor optical functional element of a loading resistor integrated type, at least one loading resistor is integrated with the optical functional element. The optical functional element has a structure in which a phototransistor and a light emitting diode are adjacent to each other and are integrated with each other, or a phototransistor and a laser diode are adjacent to each other and are integrated with each other. The optical functional element is characterized in that light is fed back from a light emitting portion of the optical functional element to a light receiving portion thereof and a semiconductor layer is formed as the loading resistor in an uppermost layer of the optical functional element. The loading resistor can be manufactured by using the same manufacturing process as the optical functional element.

Abstract: A quantum well infrared photodetector comprises multiple quantum well detectors formed within a single P-N structure forward-biased by an external voltage source, for directly converting infrared radiation having a wavelength in the range of approximately 4-15 .mu.m into visible radiation or near infrared radiation. Multiple quantum well detectors disposed between the P-N contact layers are comprised of alternating gallium arsenide (GaAs) quantum well layers, aluminum gallium arsenide (AlGaAs) barrier layers and alternatively, a blocking layer of aluminum arsenide (AlAs) positioned between a last aluminum gallium arsenide (AlGaAs) barrier layer and the N contact layer; and are forward-biased by the external voltage source in order to produce band-gap luminescence by radiative recombination of excess carriers representative of electrons and holes in the N contact layer when the P contact layer is illuminated with optical energy of incident infrared radiation.

Abstract: Dual function diodes based on conjugated organic polymer active layers are disclosed. When positively biased the diodes function as light emitters. When negatively biased they are highly efficient photodiodes. Methods of preparation and use of these diodes in displays and input/output devices are also disclosed.

Abstract: A multiple quantum well birefringent spatial light modulator has a substrate, multiple quantum well layers thereon, contacts for applying a biasing electric field across the multiple quantum well layers; and a component for varying the biasing electric field to produce birefringence in the multiple quantum well layer enhanced by the Stark effect and thereby effecting modulation of light exiting therefrom. The electric field may be varied directly by varying the voltage applied across the contacts or by providing a photodetector in series with the multiple quantum well layers and using a writing beam impinging on a photodetector to vary the field.

Abstract: Novel semiconductor devices are monolithically defined with p-type and n-type wide bandgap material formed by impurity induced layer disordering of selected regions of multiple semiconductor layers. The devices are beneficially fabricated by simultaneously forming the n-type and p-type layer disordered regions with sufficiently abrupt transitions from disordered to as-grown material. The novel devices include a heterojunction bipolar transistor monolithically integrated with an edge emitting heterostructure laser or a surface emitting laser, a heterostructure surface emitting laser, a heterostructure surface emitting laser having active distributed feedback, devices containing multiple buried layers which are individually contacted such as p-n junction surface emitting lasers, carrier channeling devices, and "n-i-p-i" or hetero "n-i-p-i" devices, and novel interdigitated structures, such as optical detectors and distributed feedback lasers.

Abstract: Disclosed is an ultrafast optical switching device having two types of multiple quantum well structures to be connected with each other, the device comprising a semi-insulating substrate; and a first and a second multiple quantum well structure formed sequentially on the substrate and united with each other to produce a double-junction multiple quantum well structure. Each of the multiple quantum well structures has nonlinear optical effects and two life time constants present while switching off in the device. One of the life time constants corresponds to a short life time constant to be determined dependent on electrons in the double-junction multiple quantum well structure and the other of the life time constants corresponds to a long life time constant to be determined dependent on holes and lattices therein.

Abstract: A semiconductor optical device including multilayer semiconductor device regions formed on a surface of a semiconductor substrate which act as an optical device respectively, and diffraction gratings formed on a back of the substrate optically coupled with at least one of said regions through the substrate. The regions have a function such as light emitting, light receiving, light amplification or light switching. The regions and gratings can be respectively formed on the surface and the back, monolithicaly, and polishing of the substrate provides a suitable thickness so that the regions and the gratings may be optically coupled with each other. The regions and gratings may be arranged at the optimum positions in the direction parallel to the substrate. Extremely precise alignment of its components and many channels can be easily obtained with compact size.

Abstract: An integrated optical intensity modulator. The modulator is an optical waveguide on a semi-insulating substrate and having a core layer for transmitting an optical signal. The modulator includes contiguous the core layer an active cladding which has a multicoupled quantum well structure. The multicoupled quantum well includes at least one pair of quantum wells separated by a barrier. The modulator further includes first and second additional claddings wherein the core layer and the active cladding are interposed between the additional claddings. A voltage source generates an electric field through the active cladding which varies the refractive index of the active cladding as a function of the strength of the electric field for modulating the optical signal.

Abstract: A surface emitting photonic switching structure includes an intermediate semiconductor structure having pn junction is sandwiched between a first semiconductor multi-layer film mirror (DBR1) and a second semiconductor multi-layer film mirror (DBR2). A pair of electrodes are provided to the intermediate semiconductor structure and the pn junction therein is applied with reverse bias voltages for changing the effective optical length of the intermediate semiconductor structure so as to change transmission wavelength of light incident on the second multi-layer film mirror or the first multi-layer film mirror. The structure can be two-dimensionally integrated, be compact and is capable of operating with low voltages.

Abstract: A semiconductor light emitting diode (LED) has a pn junction, a pin junction or a similar junction formed in a polycrystalline layer with a large grain size. The LED is produced on an amorphous, ceramic, polycrystalline or monocrystalline substrate according to a crystalline growth method and light is emitted by injecting an electric current into the junction.

Abstract: An object of the invention to vary a light absorption coefficient within wider limits in a light absorption control semiconductor device. The device includes at least three quantum wells Q1, Q2, Q3. The width of the respective quantum wells and barriers is set such that wave functions of electrons in the respective quantum wells interact in a resonance state where the quantized energy levels in either one of conduction and valence bands are matched. In addition, the width and material of the respective quantum wells are set so that one of the bands is brought into the resonance state where the quantized energy levels at the respective quantum wells are matched in a state where no electric field is applied or a state where a suitable electric field is applied in a direction perpendicular to the junctions. The light absorption is changed by controlling components of the electric field perpendicular to the junctions.

Abstract: The invention provides a heterostructure optoelectronic switching device showing a switch operation in response to a light injection for a subsequent light emission. The switching device comprises a pair of first and second bipolar transistors made of semiconductors showing a direct band-to-band transition. Each of the first and second bipolar transistors comprises collector and emitter layers and a base layer having a narrower energy band gap than energy band gaps of the collector and emitter layers. The base layers of the first and second bipolar transistors are connected to the collector layers of the second and first bipolar transistors respectively to allow the device to have a positive feedback feature. The emitter layers of the first and second bipolar transistors are connected to a first terminal.

Abstract: A light-emitting diode, in which light is emitted from a side opposite to a substrate, includes a compound semiconductor substrate of a first conductivity type, a lower cladding layer formed on the substrate end consisting of InGaAlP of the first conductivity type, a light-emitting layer formed on the lower cladding layer and having a quantum well structure constituted by alternately stacking barrier layers and eight or more quantum well layers, and an upper cladding layer formed on the light-emitting layer and consisting of InGaAlP of a second conductivity type.

Abstract: An optical head for writing and/or reading information on and/or from an optical record medium such as a magneto-optical record medium including a semiconductor substrate, a semiconductor laser mounted on a surface of the semiconductor substrate for emitting a laser beam, an objective lens for projecting the laser beam onto the optical record medium as a fine spot, a plurality of photodetectors firmed in the surface of the semiconductor substrate, and an optical block arranged on said semiconductor substrate to form an integral unit together with said semiconductor substrate. The optical block includes a hologram for diffracting a return beam reflected by said magneto-optical record medium and a polarization beam splitting plane arranged in substantially parallel with an optical axis of a zero order beam emanating from the hologram for splitting a pupil of the hologram.

Abstract: Various novel lift-off and bonding processes (60, 80, 100) permit lift-off of thin film materials and devices (68), comprising In.sub.x Ga.sub.1-x As.sub.y P.sub.1-y where 0<x<1, and 0<y<1, from a growth substrate (62) and then subsequent alignable bonding of the same to a host substrate (84). As a result, high quality communication devices can be fabricated for implementing a three dimensional electromagnetic communication network within a three dimensional integrated circuit cube (10), an array (90) of optical detectors (98) for processing images at very high speed, and a micromechanical device (110) having a platform (114) for steering or sensing electromagnetic radiation or light.

Abstract: An optical semiconductor device is disclosed which includes a semiconductor laser having at least an active layer, reflecting means formed on the semiconductor laser for reflecting internal feedback light generated from the semiconductor laser and at least two phototransistors formed on the reflecting means for detecting light having a wavelength substantially identical to that of laser light oscillated from the active layer.

Abstract: A single-crystal, monolithic, tandem, multi-color optical transceiver device is described, including (a) an InP substrate having upper and lower surfaces, (b) a first junction on the upper surface of the InP substrate, (c) a second junction on the first junction. The first junction is preferably GaInAsP of defined composition, and the second junction is preferably InP. The two junctions are lattice matched. The second junction has a larger energy band gap than the first junction. Additional junctions having successively larger energy band gaps may be included. The device is capable of simultaneous and distinct multi-color emission and detection over a single optical fiber.

Abstract: In a ridge type or buried hetero type waveguide structure, a semiconductor layer functioning as one selected from a guiding layer, an absorption layer and an active layer includes InGaAsP mixed crystal, and semiconductor cladding layers include InGaAsP mixed crystal having a bandgap energy larger than that of the InGaAsP crystal layer included in the semiconductor layer functioning as one selected therefrom.

Abstract: The invention provides a semiconductor optical surface transmission device comprising a laser element and a photo-transistor element formed on a semiconductor substrate through which light transmissions are made. Each of the laser element and the photo-transistor element has top and bottom reflective mirrors, but the bottom reflective mirror of the photo-transistor element includes a phase inversion layer to form a double resonator for detecting injection lights in a wide range of those wavelength at a high efficiency of absorption of the injection lights.

Abstract: An optical-electronic integrated circuit device capable of three-dimensionally transmitting optical signals between plural semiconductor substrates on each of which an integrated circuit is previously formed. At least one of the light emitting elements and the light receiving elements are formed on the semiconductor substrate which transmits the light propagated between these elements. In this manner, signals may be transmitted in a direction perpendicular to the semiconductor substrate even without specifically processing the semiconductor substrate. Additionally, signal distortion, transmission losses, mutual intervention or delay are not incurred.

Abstract: An article and method for manufacturing an optical reading head (400,500) including an optically transparent substrate (100) with a first surface (103) and a second surface (116), wherein the first surface (103) and the second surface (116) are joined at an angle. Depositing a plurality of layers having an upper portion (114), a middle portion (111, 112, 113), and a lower portion (101) that are optically active on the first and second surfaces (103, 116) of the optically transparent substrate (100). Forming light emitting devices (406, 407) in the plurality of layers on the second surface (116), thereby generating light emitting devices (406, 407) on the angle in the plurality of layers of the second surface (116). Positioning a detection device (402) in a normal plane to the first surface (103).

Abstract: A diode laser of the buried heterostructure type with transverse injection and a lateral bipolar transistor structure are monolithically and coaxially formed in the same set of semiconductor layers to make an integral laser device that emits a constant level of optical power stabilized against unpredictable variations. The base region of the transistor structure is formed coaxially with the laser waveguide, so that laser power passes into or through the transistor base. Electrical feedback is provided from the transistor to the laser via a resistor between the collector of the transistor and the anode of the laser, thereby controlling the current delivered by an external current source to the laser.

Abstract: A multiple quantum well optical modulator comprising a multiple quantum well structure embedded in the intrinsic region of an s-i-n+ semiconductor. The s-i-n+ structure causes an electric field to be applied to the multiple quantum well structure which causes uncoupling of the el energy confined level of one layer and the x level of the adjacent layer, thereby changing the absorption of the light and causing modulation thereof.