Abstract: An optical modulator includes an emitter layer with N-type doping having a first bandgap energy; a base layer with P-type doping having a second bandgap energy; a sub-emitter layer disposed between the emitter layer and the base layer, wherein the sub-emitter layer has a third bandgap energy that is less than both the first bandgap energy and the second bandgap energy. The sub-emitter layer provides a barrier to electrons flowing from the emitter layer, while allowing photo-generated holes to recombine in the sub-emitter layer thereby mitigating current amplification.

Abstract: A semiconductor optical device includes: a buried layer having a side surface, an upper surface, and an intermediate region; an insulating film on the upper surface of the buried layer; and an electrode including a mesa electrode, a pad electrode, and a lead-out electrode. The upper surface of the buried layer has an outer edge including a first edge extending along the first direction and a second edge extending along a second direction. The intermediate region includes an upright surface that stands straight between the side surface and the first edge, and a slope surface that slopes more gently than the upright surface and extends downward from the second edge. The lead-out electrode includes a portion on the insulating film and connected to the pad electrode, another portion on the intermediate region and through the slope surface, and another portion connected to the mesa electrode.

Abstract: A method is provided for operating one or more one solid-state electro-optic device to provide an electrically switching shutter. The method includes forming an alternating stack of first semiconductor layers having a first dopant and second semiconductor layers having a second dopant to form at least one superlattice semiconductor device. The method further includes applying to the at least one superlattice semiconductor device a first voltage to induce a transparent state of the alternating stack such that light is transmitted through the alternating stack, and applying to the at least one superlattice semiconductor device a second voltage different from the first voltage to induce an opaque state of the alternating stack such that light is inhibited from passing through the alternating stack.

Abstract: A device includes two or more waveguide portions that are adjacent to each other, and each of the two or more waveguide portions includes a first n-doped semiconductor structure and a p-doped semiconductor structure in contact with the first n-doped semiconductor structure at a bottom surface and two lateral walls on opposite ends of the first n-doped semiconductor structure. The device includes an undoped semiconductor structure in contact with each of the p-doped semiconductor structures and free of contact with each of the first n-doped semiconductor structures, and the undoped semiconductor structure includes an optical waveguide core embedded within the undoped semiconductor structure. The device includes a second n-doped semiconductor structure in contact with the undoped semiconductor structure and free of contact with each of the first n-doped semiconductor structures and the p-doped semiconductor structures.

Abstract: Disclosed is a system and method for solid-state 2D optical phased arrays (OPAs), which are fabricated from In-rich In1-xGaxN/GaN multiple quantum wells (MQWs). In-rich InxGa1-xN alloys possess the unique properties of exceptionally high free-carrier-induced refractive index (n) change and low optical loss. InGaN/GaN MQW pixels play the role of using a very small fraction of a laser beam to modulate the phase of the laser beam. The phase of each MQW pixel in the OPA is controlled independently via electro-optic effect through the integration between OPA pixels with a Laterally Diffused MOSFET (LDMOS) integrated circuit driver to achieve the manipulation of the distribution of optical power in the far field. The present invention is applicable to a wide range of applications, including the operation of LIDAR systems, laser weapons, laser illuminators, and laser imaging systems.

Abstract: An electro-absorption modulator of the invention is an electro-absorption modulator which is formed on an InP substrate and modulate incident light according to a voltage applied to that modulator, and which comprises a light absorbing layer for absorbing a portion of the incident light by using an electric field generated by the applied voltage; wherein the light absorbing layer is comprised of a ternary or more complex III-V semiconductor mixed crystal that does not contain Al but contains Bi.

Abstract: Optoelectronic apparatus includes a substrate and an array of light-emitting elements formed on a semiconductor die and mounted on the substrate, wherein the light-emitting elements are driven by separate, respective conductors, which are formed on the substrate. A controller drives the light-emitting elements selectively by applying drive signals to the respective conductors in order to create a pattern. One or more optical elements are mounted so as to receive light emitted from the array of light-emitting elements and include at least one diffractive optical element (DOE) configured to project the received light from the first optical element so as to create multiple replicas of the pattern, which fan out over a predefined angular range.

Abstract: In one embodiment, an electro-absorption modulator is configured to receive an optical light from an optical light source and outputs a modulated optical signal. The electro-absorption modulator includes a bias voltage that is used to set optimum predetermined modulation performance and an output power of the electro-absorption modulator. A controller is configured to measure a bias current of the optical light source and use a change of the bias current to determine a detuning change that occurs between the electro-absorption modulator and the optical light source. The controller uses the detuning change to automatically control the bias voltage of the electro-absorption modulator to maintain the predetermined modulation performance and maintain the output power of the electro-absorption modulator.

Abstract: A display module is disclosed. The display module includes a substrate, a plurality of micro light-emitting diodes (micro-LEDs) disposed on the substrate and configured to radiate light, a reflective layer surrounding a lateral surface of each of the plurality of micro-LEDs, and a light blocking layer disposed on the reflective layer.

Abstract: Provided is an optical module comprising a plate-like metal stem and a semiconductor optical modulation element mounted to a dielectric substrate provided on one side of the metal stem, wherein the metal stem has a metal stem penetration section in which a metal lead pin is inserted coaxially in a penetration hole which is formed in the metal stem and a dielectric member is provided to fill the penetration hole around the outer circumference of the lead pin, and a signal for modulation is supplied to the semiconductor optical modulation element connected in parallel with a terminal matching circuit, from the other side of the metal stem via the metal stem penetration section, wherein the terminal matching circuit is configured by a series connecting body which is comprised of a first resistor and a parallel body which is comprised of a second resistor and a capacitor.

Abstract: The present disclosure relates to a sensor chip and an electronic apparatus each of which enables carriers generated through photoelectric conversion to be efficiently used. At least one or more avalanche multiplication regions multiplying carriers generated through photoelectric conversion are provided in each of a plurality of pixel regions in a semiconductor substrate, and light incident on the semiconductor substrate is condensed by an on-chip lens. Then, a plurality of on-chip lenses is arranged in one pixel region. The present technology, for example, can be applied to a back-illuminated type CMOS image sensor.

Abstract: A spatial light modulator (SLM) comprised of a 2D array of optically-controlled semiconductor nanocavities can have a fast modulation rate, small pixel pitch, low pixel tuning energy, and millions of pixels. Incoherent pump light from a control projector tunes each PhC cavity via the free-carrier dispersion effect, thereby modulating the coherent probe field emitted from the cavity array. The use of high-Q/V semiconductor cavities enables energy-efficient all-optical control and eliminates the need for individual tuning elements, which degrade the performance and limit the size of the optical surface. Using this technique, an SLM with 106 pixels, micron-order pixel pitch, and GHz-order refresh rates could be realized with less than 1 W of pump power.

Abstract: Aspects of the invention are directed to an electro-optical device having a layer structure including a substrate, an electrically insulating layer on top of the substrate, a bonding layer on top of the electrically insulating layer, a Pockels layer on top of the bonding layer, a waveguide core on top of the Pockels layer, and a cladding layer cladding both the waveguide core and the Pockels layer, the latter coated by the cladding layer. The Pockels layer is a layer of a crystalline first material having a Pockels coefficient between 10 pm/V and 10 000 pm/V. The waveguide core includes a second material, which can be crystalline. The device can be adapted to optically couple radiation into and/or from the waveguide core. Each of the first material and the second material has a larger refractive index than the electrically insulating layer and the cladding layer for said radiation.

Abstract: A flexible polymeric film includes a reinforcement layer and a base layer. The reinforcement layer includes a lamella and a plurality of columns. The columns are on a surface of the lamella. Each of the columns extends in a direction and is separated from a neighboring column by a gap. The base layer is coupled to the columns and portions of the surface of the lamella in the gaps between the columns. The base layer is less rigid than the reinforcement layer. The flexible polymeric film can be produced by spraying a precursor onto a substrate. A layer of the precursor is formed on the substrate and exposed to an energy beam to form a preliminary film on the substrate. The columns can be formed from a plurality of portions of the preliminary film. The lamella is formed on top of the preliminary film that is formed with the columns.

Abstract: A cooling package in a power module comprises a first side for placing one or more semiconductor components; one or more holes for placing one or more magnetic components; and a second side with one or more connection parts. Therefore, all components of a power module which need to dissipate the heat have two thermal dissipation paths, therefore the heat inside the module can be greatly reduced.

Abstract: An optical phase shifter according to an embodiment for achieving the object of the present disclosure includes a first semiconductor layer formed on a substrate, a second semiconductor layer having opposite polarity to the first semiconductor layer, an insulating layer formed between the first semiconductor layer and the second semiconductor layer, and including ferroelectrics, a first electrode connected to the first semiconductor layer, and a second electrode connected to the second semiconductor layer. According to an embodiment, the introduction of ferroelectric materials to a semiconductor-insulator-semiconductor (SIS) optical phase shifter brings about improvement in charge collection efficiency resulting from the negative capacitance effect, thereby achieving higher phase modulation efficiency and lower power consumption. Additionally, it is possible to realize a new structure of optical switch or modulator device through design changes of the type of ferroelectrics and the structural variables.

Abstract: A display for displaying a wide Field of View (FoV) scene including a holographic image within the scene, including a first Spatial Light Modulator (SLM) and an optical system for producing a first holographic image at a center of a displayed scene, and a second image display for producing at least a first additional image adjacent to the first holographic image. In some embodiments an augmented reality display is used for the displaying of the first holographic image at the center of a field of view and the second image adjacent to the first holographic image. In some embodiments a virtual reality display is used for the displaying of the first holographic image near the center of a field of view and the second image adjacent to the first holographic image. Related apparatus and methods are also described.

Abstract: The present disclosure generally relates to a method, and apparatus implementing the method for removing particulate accumulation from an optical element of a micro electromechanical systems (MEMS) package. The method may select a cleaning mode based, at least in part on, one or more of output of a sensor or a maintenance routine. Cleaning modes may include actuating, using an actuator of the MEMS package, one of a plurality of motion modes across the optical element. Optionally, the cleaning mode may include applying, using a power source of the MEMS package, a charge to the optical element. The disclosed techniques may enable the MEMS package to automatically and dynamically remove particulate matter without introducing additional mechanical elements.

Abstract: A method for manufacturing a semiconductor device comprises forming first groove, depositing, and ion-implanting. At the step of forming the first groove, the first groove is formed in a stacked body comprising a gallium nitride (GaN)-based first semiconductor layer containing an n-type impurity and a gallium nitride (GaN)-based second semiconductor layer stacked on the first semiconductor layer and containing a p-type impurity. The first groove has a bottom portion located in the second semiconductor layer. At the depositing step, a p-type impurity is deposited on side portion and the bottom portion of the first groove. At the ion-implanting step, a p-type impurity is ion-implanted into the first semiconductor layer through the first groove.

Abstract: A controllable frequency selective surface. The frequency selective surface has a plurality of conductive patches with integrated circuits straddling gaps between, and connected to, pairs of patches separated by gaps. Each integrated circuit presents a controllable impedance and as a result the characteristics of the frequency selective surface are controllable.

Abstract: Methods are provided for fabricating a HEMT (high-electron-mobility transistor) that involve sequential epitaxial growth of III-nitride channel and barrier layers, followed by epitaxial regrowth of further III-nitride material through a window in a mask layer. In examples, the regrowth takes place over exposed portions of the channel layer in the source and drain regions of the device, and the regrown material has a composition different from the barrier layer. In other examples, the regrowth takes place on the barrier layer, only in the access region or regions. Devices made according to the disclosed methods are also provided.

Abstract: A laser-diode device includes a substrate; at least one first cladding layer placed on the substrate; an active layer placed on the first cladding layer and arranged to emit a radiation; at least one second cladding layer placed on the active layer, said cladding layers being adapted to form a heterojunction; a first terminal facet and a second terminal facet placed transversally relative to the cladding layers and to the active layer; a periodic structure, placed in proximity to the second terminal facet and within the second cladding layer, and belonging to an optical cavity, wherein the first terminal facet represents the output mirror from which the radiation generated by the active layer exits, and the second terminal facet, integrated by the periodic structure, represents a second mirror having high reflectivity, so that the radiation produced by the active layer exits almost totally through the first mirror.

Abstract: A light modulator may include: a light modulating unit formed as a pixel-array type by using a PIN diode including multiple quantum wells including a Group-III nitride semiconductor material, and configured to modulate light by electroabsorption; and/or a control unit including a transistor configured to control voltage applied to the PIN diode of the light modulating unit. The PIN diode and the transistor may be arrayed in an active matrix form.

Abstract: An electro-optic modulator device includes a modulation region, a reflecting region, a conductive line and an anti-reflecting region. The modulation region includes a doped region. The reflecting region is over the modulation region. The conductive line is connected to the doped region. The conductive line extends through the reflecting region. The anti-reflecting region is on an opposite surface of the modulation region from the reflecting region.

Abstract: A method of generating THz radiation includes the steps of generating optical input radiation with an input radiation source device (10), irradiating a first conversion crystal device (30) with the optical input radiation, wherein the first conversion crystal device (30) is arranged in a single pass configuration, and generating the THz radiation having a THz frequency in the first conversion crystal device (30) in response to the optical input radiation by an optical-to-THz-conversion process, wherein a multi-line frequency spectrum is provided by the optical input radiation in the first conversion crystal device (30), and the optical-to-THz-conversion process includes cascaded difference frequency generation using the multi-line frequency spectrum. Furthermore, a THz source apparatus being configured for generating THz radiation and applications thereof are described.

Abstract: A photosensor for the detection of infrared radiation in the wavelength range of 1 to 1000 micrometers consists of a semiconductor substrate with a highly doped interaction volume for the incoming radiation. At the edge of this highly doped region, an extended gate electrode is placed consisting of a conducting material on top of an insulating layer. On the other side of the gate electrode, another highly doped semiconductor region is placed, acting as a charge collector. Through free carrier absorption in the interaction volume, incoming photons impart their energy on mobile charge carriers. In the case of free electrons, the gate electrode is biased slightly below the reset voltage of the interaction volume, so that the electrons carrying the additional energy of the absorbed photons can predominantly make the transition from the interaction volume across the gate electrode area to the charge collector volume.

Abstract: Dual or multi-modulation display system are disclosed that comprise projector systems with at least one modulator that may employ non-mechanical beam steering modulation. Many embodiments disclosed herein employ a non-mechanical beam steering and/or polarizer to provide for a highlights modulator.

Abstract: A reconfigurable electro-magnetic tile includes a laser layer including a plurality of lasers, and a pixelated surface comprising a plurality of metal patches and a plurality of switches, wherein each respective switch of the plurality of switches is in a gap between a first respective metal patch and a second respective metal patch, wherein each respective switch is optically coupled to at least one respective laser of the plurality of lasers, and wherein each switch of the plurality of switches comprises a phase change material.

Abstract: An epitaxial wafer which allows manufacture of a photodiode having suppressed dark current and ensured sensitivity, and a method for manufacturing the epitaxial wafer, are provided. The epitaxial wafer of the present invention includes: a III-V semiconductor substrate; and a multiple quantum well structure disposed on the substrate, and including a plurality of pairs of a first layer and a second layer. The total concentration of elements contained as impurities in the multiple quantum well structure is less than or equal to 5×1015 cm?3.

Abstract: A projection system is provided that uses an additional light valve in series with at least one color sub-assembly and respective light valve in order to increase the contrast of a projected image, wherein bit sequences are generated for the additional light valve that do not result in interference with the respective light valve bit sequences.

Abstract: A display media including a pixel layer containing subpixels for different optical bands composed of nano-scale structures and an intensity control layer that can pattern the luminance of the subpixels. The display media includes a substrate layer, a sub-wavelength substrate supported by the substrate layer and including subpixels, each subpixel defined by at least one sub-wavelength structure having at least one specific optical property including a specific optical band, at least two of the subpixels having a different specific optical property, and an intensity control layer to individually control an amount of luminance of each individual subpixel in a pattern. Some of the subpixels may have colors that define a color space, while some other subpixels may have an invisible radiation spectrum band. For example, the display media can allow both overt information (color images) and covert information to be embedded together with high density.

Abstract: A method of mounting a plurality of semiconductor or microelectronic chips or dies, the method including providing a carrier, temporarily adhering the plurality of semiconductor or microelectronic chips or dies to the carrier with active faces of the chips or dies facing towards the carrier, covering backsides of the chips and filling empty spaces between the chips or dies with a metallic material to thereby define an assembly of the chips or dies and the metallic material, and releasing the assembly from the carrier, wherein each chip or die comprises at least one bonding ring higher than a height of the active face of the respective chip or die or any connections on the active face of the respective chip or die.

Abstract: A modulating apparatus includes a branch that branches input light; a first modulating unit that modulates the phase of a first branch obtained by the branch; a second modulating unit that modulates a second branch obtained by the branch; a third modulating unit that is connected in series to the first modulating unit, transmits the first branch without branching the first branch, modulates the phase of light transmitted by controlling a refractive index of the light transmitted; a fourth modulating unit that is connected in series to the second modulating unit, transmits the second branch without branching the second branch, and modulates the phase of a light transmitted by controlling a refractive index of the light transmitted; and a coupler that couples the first branch modulated by the first and the third modulating units and the second branch modulated by the second and the fourth modulating units, at different intensities.

Abstract: A method to align an optical device optically with an interference device is disclosed. The method includes steps of: selecting one of arm waveguides, biasing rest of arm waveguides to cause optical absorption thereat, and aligning the optical device optically with the selected arm waveguide.

Abstract: An object of the present invention is to provide a temperature-independent optical frequency shifter for generating sub-carriers with a miniaturizable configuration, as well as to provide an all-optical OFDM modulator using the same that is compact, has low temperature dependence, and is even compatible with different frequency grids. Provided is an optical frequency shifter and an optical modulator using the same, the optical frequency shifter comprises one input optical port, a 1-input, 2-output optical coupler optically connected thereto, two Mach-Zehnder modulation units individually optically connected to the two outputs thereof, a 2-input, 2-output optical coupler optically connected to the individual outputs thereof, and two output optical ports optically connected to the outputs thereof, wherein the two Mach-Zehnder modulation units are driven by periodic waveforms at the same frequency whose phases differ from each other by (2p+1)?/2 (p: integer).

Abstract: A first clock modulator branches a light beam, varies a phase difference of the resulting light beams according to a first clock, and causes interference of the light beams. A second clock modulator branches a light beam from the first clock modulator and synchronized with the first clock, varies a phase difference of the resulting light beams according to a second clock, and causes interference of the light beams. A third clock modulator branches a light beam from the first clock modulator and inversely synchronized with the first clock, varies a phase difference of the resulting light beams according to a third clock, and causes interference of the light beams. The second clock and the first clock have identical cycles and differing phases. The third clock and the second clock have phases that differ by a 1/2 cycle. Four data modulators modulate the light beams from the clock modulators.

Abstract: An optical device has a tube including a tube wall defining a viewing bore. A light source is in communication with the viewing bore for illuminating an aim point visible in the viewing bore. A control system includes a circuit board supported by the tube exterior of the viewing bore. The control system is in communication with the light source for controlling brightness of the illuminated aim point. The control system includes a light sensor mounted to the circuit board and extending from the circuit board through the tube wall into the viewing bore for sensing light in the viewing bore.

Abstract: Devices are described including a component comprising an alloy of AlN and AlSb. The component has an index of refraction substantially the same as that of a semiconductor in the optoelectronic device, and has high transparency at wavelengths of light used in the optoelectronic device. The component is in contact with the semiconductor in the optoelectronic device. The alloy comprises between 0% and 100% AlN by weight and between 0% and 100% AlSb by weight. The semiconductor can be a III-V semiconductor such as GaAs or AlGaInP. The component can be used as a transparent insulator. The alloy can also be doped to form either a p-type conductor or an n-type conductor, and the component can be used as a transparent conductor. Methods of making and devices utilizing the alloy are also disclosed.

Abstract: A thermally stabilized, high speed, micrometer-scale silicon electro-optic modulator is provided. Methods for maintaining desired temperatures in electro-optic modulators are also provided. The methods can be used to maintain high quality modulation in the presence of thermal variations from the surroundings. Direct current injection into the thermally stabilized electro-optic modulator is used to maintain the modulation performance of the modulator. The direct injected current changes the local temperature of the thermally stabilized electro-optic modulator to maintain its operation over a wide temperature range.

Abstract: A modulation method, especially an optical modulation method, using the principle of discrete IQ modulation. The modulation method includes generating a carrier signal (Sc) and splitting the carrier signal at a splitting position in an I branch signal and a Q branch signal; modulating the amplitude of the I branch signal according to a first modulation signal and modulating the amplitude of the Q branch signal according to a second modulation signal, each of the first and second modulation signals being arranged to adopt a given number of values according to a given number of constellation points of a given modulation scheme; phase shifting the signal in the Q branch versus the signal in the I branch; and combining the signals in the I branch and Q branch at a combining position. The combined modulated signal (Stx,mod) is arranged to be transmitted over a transmission path.

Abstract: An optical modulator unit, an optical modulator, and a method of fabricating are provided. The optical modulator unit includes a first contact layer transmitting infrared rays, a lower reflection layer disposed on the first contact layer, an active layer, including a multiple quantum well, disposed on the lower reflection layer, and an upper reflection layer disposed on the active layer. The optical modulator includes a plurality of optical modulator units sharing the first contact layer. The method includes sequentially stacking a first contact layer, a lower reflection layer, an active layer, an upper reflection layer, and a second contact layer on a substrate; etching the second contact layer, the upper reflection layer, the active layer, and the lower reflection layer, exposing a surface of the first contact layer; forming a first electrode on the first contact layer; and forming a second electrode on the second contact layer.

Abstract: [PROBLEM] Providing an optical source that outputs optical frequency modulated light having a constant output optical intensity. [MEANS FOR SOLVING THE PROBLEM] Provided is a light source apparatus that outputs an optical signal having an optical frequency corresponding to a frequency control signal, the light source apparatus including a laser light source section that outputs laser light having an optical frequency corresponding to the frequency control signal; and an optical intensity adjusting section that compensates for intensity change of the laser light to output laser light in which the intensity change caused by a change in the optical frequency is restricted.

Abstract: To efficiently apply jitter to an optical signal using a simple configuration, provided is an optical signal output apparatus that outputs an optical pulse pattern signal including jitter, the optical signal generating apparatus comprising a light source section that outputs an optical signal having an optical frequency corresponding to a frequency control signal; an optical modulation section that modulates the optical signal output by the light source section, according to a designated pulse pattern; and an optical jitter generating section that delays an optical signal passed by the optical modulation section according to the optical frequency, to apply jitter to the optical signal.

Abstract: An optical modulator, methods of manufacturing and operating the same, and an optical apparatus including the optical modulator are disclosed. The optical modulator includes an electro-optical converter and an optical-electric converter, stacked perpendicular to a substrate, and a gate transistor. The gate transistor gates a signal transmitted to the electro-optical converter from the optical-electric converter and allows charges generated in the optical-electric converter and charges remaining in the electro-optical converter to flow while bypassing the electro-optical converter when gating ON is performed.

Abstract: A digital data transmission device is provided comprising optical waveguide architecture, a sideband generator, a modulation controller, an optical filter, a data mapping unit, and a phase controller. The optical waveguide architecture is configured to direct an optical signal through the sideband generator and the optical filter. The sideband generator comprises an electrooptic interferometer comprising first and second waveguide arms. The modulation controller is configured to generate an electrical drive signal to drive the sideband generator at a control voltage that is substantially larger than V? to generate optical frequency sidebands about a carrier frequency of the optical signal. The optical filter is configured to discriminate between the optical frequency sidebands and the optical carrier frequency such that optical sidebands of interest can be directed through the optical waveguide architecture as an optical millimeter wave signal.

Abstract: A device comprising: two mutually immiscible conductive liquids arranged to form an interface therebetween; a plurality of nanoparticles localised at the said interface, the said nanoparticles each having a first region formed of a semiconductor having a first bandgap, the first region being surrounded by a second region having a second bandgap, the second bandgap being larger than the first bandgap; and means for applying an electric field to the said nanoparticles and thus, through the Stark effect, altering the optical absorption or emission characteristics of the nanoparticles.

Abstract: Optical modulator having wide bandwidth based on Fabry-Perot resonant reflection is disclosed. The optical modulator includes: a bottom Distributed Bragg Reflector (DBR) layer; a top DBR layer including at least one layer, and a modified layer; and an active layer disposed between bottom and top DBR layers, wherein the at least one layer includes at least one pair of a first refractive index layer having a first refractive index and a second refractive index layer having a second refractive index, the modified layer includes at least one pair of a third refractive index layer having a third refractive index and a fourth refractive index layer having a fourth refractive index, the third and the fourth refractive indexes being different, and at least one of the third and the fourth refractive index layers has a second optical thickness that is not ?/4 or that is not an odd multiple thereof.

Abstract: An optical image modulator and a method of manufacturing the same. The optical image modulator includes a substrate, an N electrode contact layer formed on the substrate, a lower distributed Bragg reflection (DBR) layer, a quantum well layer, an upper DBR layer, and a P electrode contact layer sequentially stacked on the N electrode contact layer, a P electrode formed on the P electrode contact layer, and an N electrode formed on the N electrode contact layer. The N electrode is a frame that surrounds the lower DBR layer.

Abstract: An uncooled optical semiconductor device includes: a semiconductor laser outputting laser light; an electric field absorption optical modulator absorbing light depending on a voltage applied to the electric field absorption optical modulator; a monitor photodiode monitoring backlight of the semiconductor laser; an auto power control circuit feeding back current of the monitor photodiode to a bias current supplied to the semiconductor laser; and a bias circuit feeding back an average value of a light absorption current to control a bias voltage applied to the electric field absorption optical modulator. The light absorption current is generated when the electric field absorption optical modulator absorbs the laser light.

Abstract: An optical modulator unit, an optical modulator, and a method of fabricating are provided. The optical modulator unit includes a first contact layer transmitting infrared rays, a lower reflection layer disposed on the first contact layer, an active layer, including a multiple quantum well, disposed on the lower reflection layer, and an upper reflection layer disposed on the active layer. The optical modulator includes a plurality of optical modulator units sharing the first contact layer. The method includes sequentially stacking a first contact layer, a lower reflection layer, an active layer, an upper reflection layer, and a second contact layer on a substrate; etching the second contact layer, the upper reflection layer, the active layer, and the lower reflection layer, exposing a surface of the first contact layer; forming a first electrode on the first contact layer; and forming a second electrode on the second contact layer.