Abstract: A photo detector includes: a semiconductor substrate having a first principal face and a second principal face; a photo detection area formed on the first principal face of the semiconductor substrate; a negative electrode electrically connected with the photo detection area; a positive electrode; a beveled face formed at least one edge portion of the first principal face of the semiconductor substrate; and a reflector formed on the second principal face of the semiconductor substrate, wherein incident light from outside of the semiconductor substrate, enters the semiconductor substrate at a side face of the photo detector while being refracted at the beveled face, and thereafter is reflected from the reflector so as to reach the photo detection area.

Abstract: The dual wavelength semiconductor laser source for an optical pickup includes: two semiconductor laser elements outputting laser beams having oscillating wavelengths different from each other; and a multiplexing waveguide, formed inside of a photonic crystal having a photonic band gap, having one output end outputting laser light at one end surface and two input ends at the other end surfaces. Output beams of the two semiconductor laser elements are coupled to the respective two input ends of the multiplexing waveguide and the two beams are outputted from the one output end of the multiplexing waveguide.

Abstract: A filter layer and a buffer layer are sequentially laminated on a first principal face of a semiconductor substrate, and an island-shaped light absorption layer and a window layer are laminated on top of the buffer layer. A diffusion region in which p-type impurities have been diffused is formed in the window layer. An n-side electrode and a p-side electrode are formed on the buffer layer and the diffusion region, respectively. A light incidence portion is formed on the buffer layer where the light absorption layer has not been formed.

Abstract: A photodetector includes semiconductor conductive layer, light-absorbing layer and wide bandgap layer, which are stacked in this order on a semi-insulating semiconductor substrate. The conductive layer has been formed on a surface region of the substrate. The photodetector further includes a doped region defined in part of the wide bandgap layer. The conductive layer has etch susceptibility different from that of the substrate.

Abstract: A filter layer and a buffer layer are sequentially laminated on a first principal face of a semiconductor substrate, and an island-shaped light absorption layer and a window layer are laminated on top of the buffer layer. A diffusion region in which p-type impurities have been diffused is formed in the window layer. An n-side electrode and a p-side electrode are formed on the buffer layer and the diffusion region, respectively. A light incidence portion is formed on the buffer layer where the light absorption layer has not been formed.

Abstract: A filter layer and a buffer layer are sequentially laminated on a first principal face of a semiconductor substrate, and an island-shaped light absorption layer and a window layer are laminated on top of the buffer layer. A diffusion region in which p-type impurities have been diffused is formed in the window layer. An n-side electrode and a p-side electrode are formed on the buffer layer and the diffusion region, respectively. A light incidence portion is formed on the buffer layer where the light absorption layer has not been formed.

Abstract: A photo-detecting device includes: a semiconductor substrate; a multilayer structure formed on the semiconductor substrate; an island-like photo-detecting region formed in at least a portion of the multilayer structure, the island-like photo-detecting region having a central portion; and a light-shielding mask formed on the semiconductor substrate so as to shield from light a portion of the island-like photo-detecting region at least excluding the central portion. The light-shielding mask comprises an upper metal film and a lower metal film, and the upper metal film and the lower metal film are at least partially isolated by an insulative film, the upper metal film and the lower metal film having different patterns.

Abstract: A light receiving device includes a semiconductor substrate, a light absorbing layer provided on the semiconductor substrate, a window layer provided on the light absorbing layer, a wavelength filter provided on the window layer, and a diffusion region provided in the wavelength filter and the window layer. A forbidden bandwidth of the wavelength filter is smaller than a forbidden bandwidth of the window layer, and a forbidden bandwidth of the light absorbing layer is smaller than the forbidden bandwidth of the wavelength filter.

Abstract: A method for fabricating a semiconductor device, in which a semiconductor chip having a first surface and a second surface substantially parallel to each other is mounted on a submount such that the first surface faces the submount, includes: a first step of applying resin to at least one of the semiconductor chip and the submount; a second step of applying a pressure to the semiconductor chip and the submount so that the semiconductor chip and the submount are bonded to each other by the resin, resulting in electrical connection therebetween; and a third step of performing at least one of a film formation process, an etching process, a patterning process, and a washing process for the second surface of the semiconductor chip.

Abstract: A demultiplexer according to the present invention includes a photonic crystalline layer, which is formed on the principal surface of a semiconductor substrate and transmits an incoming light beam with a predetermined wavelength. A wavelength at an edge of a photonic band of the photonic crystalline layer changes in a direction parallel to the principal surface of the substrate.

Abstract: A light receiving device includes a semiconductor substrate, a light absorbing layer provided on the semiconductor substrate, a window layer provided on the light absorbing layer, a wavelength filter provided on the window layer, and a diffusion region provided in the wavelength filter and the window layer. A forbidden bandwidth of the wavelength filter is smaller than a forbidden bandwidth of the window layer, and a forbidden bandwidth of the light absorbing layer is smaller than the forbidden bandwidth of the wavelength filter.

Abstract: A light absorbing layer composed of intentionally undoped n-type InGaAs and a window layer composed of intentionally undoped n-type InP are formed sequentially on a first principal surface of a semiconductor substrate composed of n-type InP. A cathode is provided on a p-type diffused region forming an island pattern in the window layer, while an anode is provided on a second principal surface of the semiconductor substrate. A side edge portion of the second principal surface of the semiconductor substrate is formed with a gradient portion having an exposed surface with a (112) plane orientation and forming an angle of 35.3° with respect to the second principal surface. The gradient portion is formed to have a mirrored surface by using an etching solution containing hydrochloric acid and nitric acid at a volume ratio of approximately 5:1 to 3:1.

Abstract: A light absorbing layer composed of intentionally undoped n-type InGaAs and a window layer composed of intentionally undoped n-type InP are formed sequentially on a first principal surface of a semiconductor substrate composed of n-type InP. A cathode is provided on a p-type diffused region forming an island pattern in the window layer, while an anode is provided on a second principal surface of the semiconductor substrate. A side edge portion of the second principal surface of the semiconductor substrate is formed with a gradient portion having an exposed surface with a (112) plane orientation and forming an angle of 35.3° with respect to the second principal surface. The gradient portion is formed to have a mirrored surface by using an etching solution containing hydrochloric acid and nitric acid at a volume ratio of approximately 5:1 to 3:1.

Abstract: A photo-detecting device includes: a semiconductor substrate; a multilayer structure formed on the semiconductor substrate; an island-like photo-detecting region formed in at least a portion of the multilayer structure, the island-like photo-detecting region having a central portion; and a light-shielding mask formed on the semiconductor substrate so as to shield from light a portion of the island-like photo-detecting region at least excluding the central portion. The light-shielding mask comprises an upper metal film and a lower metal film, and the upper metal film and the lower metal film are at least partially isolated by an insulative film, the upper metal film and the lower metal film having different patterns.

Abstract: A photo-detecting device includes: a semiconductor substrate; a multilayer structure formed on the semiconductor substrate; an island-like photo-detecting region formed in at least a portion of the multilayer structure, the island-like photo-detecting region having a central portion; and a light -shielding mask formed on the semiconductor substrate so as to shield from light a portion of the island-like photo-detecting region at least excluding the central portion. The light-shielding mask comprises an upper metal film and a lower metal film, and the upper metal film and the lower metal film are at least partially isolated by an insulative film, the upper metal film and the lower metal film having different patterns.

Abstract: A photodetector includes semiconductor conductive layer, light-absorbing layer and wide bandgap layer, which are stacked in this order on a semi-insulating semiconductor substrate. The conductive layer has been formed on a surface region of the substrate. The photodetector further includes a doped region defined in part of the wide bandgap layer. The conductive layer has etch susceptibility different from that of the substrate.

Abstract: A method for fabricating a semiconductor device, in which a semiconductor chip having a first surface and a second surface substantially parallel to each other is mounted on a submount such that the first surface faces the submount, includes: a first step of applying resin to at least one of the semiconductor chip and the submount; a second step of applying a pressure to the semiconductor chip and the submount so that the semiconductor chip and the submount are bonded to each other by the resin, resulting in electrical connection therebetween; and a third step of performing at least one of a film formation process, an etching process, a patterning process, and a washing process for the second surface of the semiconductor chip.

Abstract: Mutually parallel V grooves are formed on the upper surface of a first support member of an optical fiber array ferrule, and then an optical fiber wire is disposed in each of the V grooves. Stacked thereon is a second support member having V grooves formed on both the upper and lower surfaces thereof so as to oppose each other, the V grooves on the lower surface serving as guiding grooves. An optical fiber wire is also disposed in each of the V grooves on the upper surface of the second support member. Further stacked thereon is a third support member having V grooves formed on the lower surface thereof, so that an optical fiber array ferrule is configured. The optical fiber array ferrule as well as a surface emitting laser array are mounted on a single substrate so that an optical coupling module is configured.

Abstract: The optical module of the invention includes: a first substrate; a vertical-cavity surface-emitting laser including an upper surface, a bottom surface and a semiconductor multi-layered structure including at least a light-emitting layer, the vertical-cavity surface-emitting laser being supported on the first substrate; an electrode structure electrically connected with the bottom surface of the vertical-cavity surface-emitting laser, the electrode structure being supported on the first substrate; and a second substrate including a first bump and a second bump. In the optical module, an upper surface of the electrode structure and the upper surface of the vertical-cavity surface-emitting laser jut out from the first substrate. The second substrate is positioned with respect to the first substrate so that the first bump and the second bump come into contact with an upper surface of the electrode structure and the upper surface of the vertical-cavity surface-emitting laser, respectively.

Abstract: An electro-absorption optical modulator, where a waveguide length of the absorption layer is denoted by L, a light confinement coefficient thereof is denoted by .GAMMA., and a performance factor of the absorption layer at an applied voltage V to an absorption layer is denoted by K(V), has design parameters selected so that a relationship .vertline.K(V)-.GAMMA..multidot.L.vertline. .ltoreq.0.005 cm is satisfied in a continuous operation range of a quenching ration T.sub.Att. The waveguide length L is preferably optimizrd so as to satisfy K(V).apprxeq..GAMMA..multidot.L in the operation range.