Abstract:
Provided is a light coupling apparatus that forms an etch structure complex comprising a total reflection surface/an anti-reflection surface within a substrate to improve coupling efficiency with incident light and responsivity of a photodetector device, whereby a surface-illuminated photodetector or an edge-coupled photodetector are all integratable, and it is possible to reduce the degree of difficulty during packaging and to improve the responsivity of the photodetector at low costs.
Abstract:
Provided is an avalanche quantum intersubband transition semiconductor laser. The laser includes: a first cladding layer, a first wave guide layer, an active region, a second wave guide layer, and a second cladding layer formed on a semiconductor substrate, wherein the active region consists of multiple stacks (periods) of a unit-cell structure, which is comprised of a carrier-multiplication layer structure for multiplying carriers, a carrier guide layer structure, and an QW active region to which carriers are injected, wherein intersubband optical radiative transitions of the carriers occur. Here, the carriers multiplied while passing though the carrier-multiplication layer structure, and injected into a optical transition level of the QW active region can achieve the high population inversion effectively, thereby high laser output power can be obtained with less stacked compact structure.
Abstract:
Provided are an abrupt metal-insulator transition (MIT) device for bypassing super-high voltage noise to protect an electric and/or electronic system, such as, a high-voltage switch, from a super-high voltage, a high-voltage noise removing circuit for bypassing the super-high voltage noise using the abrupt MIT device, and an electric and/or electronic system including the high-voltage noise removing circuit. The abrupt MIT device includes a substrate, a first abrupt MIT structure, and a second abrupt MIT structure. The first and second abrupt MIT structures are formed on an upper surface and a lower surface, respectively, of the substrate. The high-voltage noise removing circuit includes an abrupt MIT device chain connected in parallel to the electric and/or electronic system to be protected. The abrupt MIT device chain includes at least two abrupt MIT devices serially connected to each other.
Abstract:
Provided are a method and structure for optical connection between an optical transmitter and an optical receiver. The method includes the steps of: forming on a substrate a light source device, an optical detection device, an optical transmission unit electrically connected with the light source device, and an optical detection unit electrically connected with the optical detection device; preparing a flexible optical transmission-connection medium to optically connect the light source device with the optical detection device; cutting the prepared optical transmission-connection medium and surface-finishing it; and connecting one end of the surface-finished optical transmission-connection medium with the light source device and the other end with the optical detection device. Fabrication of an optical package having a 3-dimensional structure is facilitated and fabrication time is reduced, thus improving productivity. In addition, since the optical transmission-connection medium is directly connected with the light source device and the optical detection device, a polishing operation or additional connection block is not required, thus facilitating mass production.
Abstract:
A method of growing a germanium (Ge) epitaxial thin film having negative photoconductance characteristics and a photodiode using the same are provided. The method of growing the germanium (Ge) epitaxial thin film includes growing a germanium (Ge) thin film on a silicon substrate at a low temperature, raising the temperature to grow the germanium (Ge) thin film, and growing the germanium (Ge) thin film at a high temperature, wherein each stage of growth is performed using reduced pressure chemical vapor deposition (RPCVD). The three-stage growth method enables formation of a germanium (Ge) epitaxial thin film characterized by alleviated stress on a substrate, a lowered penetrating dislocation density, and reduced surface roughness.
Abstract:
The present invention is related to a hot-electron photo transistor. By applying the combination of quantum dots or quantum wires with sizes, the wide spacer layers, and the blocking layers to the electron injecting barrier of the emitter, the wide range of infrared detection can be attained and the resolution of detected infrared wavelength can be increased. And by introducing the resonant tunneling quantum well structure to the base layer the selection, amplification and processing of the specific infrared frequency is possible and the reduction of the dark current is induced. Therefore, the present invention is applicable to ultra-high speed tunable infrared detectors and amplifiers, ultra-high speed switching and logic devices, high speed infrared logic devices with new features, new high-speed infrared logic devices which can reduce the number of logic devices.
Abstract:
Provided is a method of fabricating a semiconductor optical device for use in a subscriber or a wavelength division multiplexing (WDM) optical communication system, in which a laser diode (LD) and a semiconductor optical amplifier (SOA) are integrated in a single active layer. The laser diode (LD) and the semiconductor optical amplifier (SOA) are optically connected to each other, and electrically insulated from each other by ion injection, whereby light generated from the LD is amplified by the SOA to provide low oscillation start current and high intensity of output light when current is individually injected through each electrode.
Abstract:
The present invention relates to an ultra-high speed semiconductor phototransistor which comprises a substrate. A conductive collector layer, on which a collector electrode is formed, is formed on the substrate. A collector barrier layer for collector electric potential is formed on the conductive collector layer. A conductive base layer, on which a base electrode is formed, is formed on the collector electric potential barrier layer. An emitter barrier layer for emitter electric potential is formed on the conductive base layer for injecting hot-electrons onto the conductive base layer. The emitter barrier layer for emitter electric potential further comprises various sizes of quantum-dot array combination structures for absorbing an infrared ray. A blocking barrier layer positioned beneath the quantum-dot array combination structures reduces a dark current passed through the quantum-dot array combination structure. A second buffer layer positioned beneath the blocking barrier layer absorbs an electric potential change in the quantum-dot array combination structure due to the applied voltage. A conductive emitter layer, on which an emitter electrode is formed, is formed on the emitter barrier layer for emitter electric potential.
Abstract:
A method of growing a germanium (Ge) epitaxial thin film having negative photoconductance characteristics and a photodiode using the same are provided. The method of growing the germanium (Ge) epitaxial thin film includes growing a germanium (Ge) thin film on a silicon substrate at a low temperature, raising the temperature to grow the germanium (Ge) thin film, and growing the germanium (Ge) thin film at a high temperature, wherein each stage of growth is performed using reduced pressure chemical vapor deposition (RPCVD). The three-stage growth method enables formation of a germanium (Ge) epitaxial thin film characterized by alleviated stress on a substrate, a lowered penetrating dislocation density, and reduced surface roughness.
Abstract:
Provided is a method of growing a pure germanium (Ge) thin film with low threading dislocation density using reduced pressure chemical vapor deposition (RPCVD), which includes growing a Ge thin film on a silicon (Si) substrate at a low temperature, performing real-time annealing for a short period of time, and growing the annealed Ge thin film at a high temperature. The grown Ge single crystal thin film can overcome conventional problems of generation of a Si—Ge layer due to Si diffusion, and propagation of misfit dislocation to a high-temperature Ge thin film.