Abstract: To provide a low-cost and fine-property bidirectional optical transmitting/receiving module and the like, which include a de-multiplexing device that uses a V-letter shaped optical waveguide and a dielectric multilayer filter. Formation of an end face where the dielectric multilayer film is formed and separation of optical modules are performed in separate steps, and the end face at the intersection of the V-letter shaped optical waveguide, on which the dielectric multilayer filter is formed, is formed by dry etching to achieve high smoothness. Further, a cutting face of the optical module is set at a position that is isolated from the end face at least by 3 ?m. Through the above, the smooth end face is protected from roughness of the cutting face caused by a light emitting element separating step, and the dielectric multilayer filter is formed on that end face.

Abstract: An exemplary aspect of the invention is a light receiving element comprising a substrate, a light receiver absorbing light on a surface of the substrate, and a reflector reflecting the light incoming from a side of the substrate to the light receiver, wherein a reflecting surface of the reflector is inclined toward the side of the substrate in a section parallel to the surface of the substrate.

Abstract: To provide a low-cost and fine-property bidirectional optical transmitting/receiving module and the like, which include a de-multiplexing device that uses a V-letter shaped optical waveguide and a dielectric multilayer filter. Formation of an end face where the dielectric multilayer film is formed and separation of optical modules are performed in separate steps, and the end face at the intersection of the V-letter shaped optical waveguide, on which the dielectric multilayer filter is formed, is formed by dry etching to achieve high smoothness. Further, a cutting face of the optical module is set at a position that is isolated from the end face at least by 3 ?m. Through the above, the smooth end face is protected from roughness of the cutting face caused by a light emitting element separating step, and the dielectric multilayer filter is formed on that end face.

Abstract: An inexpensive and compact modulator-integrated light source is capable of obtaining an extinction ratio of 10 dB sufficient for use in optical communication without requiring an amplifier or temperature regulating mechanism. The modulator-integrated light source is composed of a semiconductor laser and modulator integrated on high-resistance semiconductor substrate 1. The electroabsorption optical modulator has P-electrode 14 and N-electrode 32 which are arranged on one surface of high-resistance semiconductor substrate 1 and to which a prescribed bias voltage is applied, and the electroabsorption optical modulator is constructed to satisfy the condition: L×B?2000 ?m·Gb/s, where L is the length of the electroabsorption optical modulator and B is the operating frequency.

Abstract: An edge emitting semiconductor laser suppresses the “beam steering” to raise its maximum output with a simple configuration. An optical waveguide serving as a resonator includes an active layer and a cladding layer. A first edge, to which one end of the waveguide is connected, serves as an emission edge. A second edge, to which the other end of the waveguide is connected, is located at an opposite side to the first edge. The waveguide includes at least two parts having different widths, one of the at least two parts being a fundamental mode section. Current injection suppressing means is provided for suppressing or controlling current injection into the active layer in at least part of the fundamental mode section. The current injection suppressing means is preferably made by a current blocking layer, a current-limiting masking layer, or a passive wave-guiding region.

Abstract: An edge emitting semiconductor laser suppresses the “beam steering” to raise its maximum output with a simple configuration. An optical waveguide serving as a resonator includes an active layer and a cladding layer. A first edge, to which one end of the waveguide is connected, serves as an emission edge. A second edge, to which the other end of the waveguide is connected, is located at an opposite side to the first edge. The waveguide includes at least two parts having different widths, one of the at least two parts being a fundamental mode section. Current injection suppressing means is provided for suppressing or controlling current injection into the active layer in at least part of the fundamental mode section. The current injection suppressing means is preferably made by a current blocking layer, a current-limiting masking layer, or a passive wave-guiding region.

Abstract: A semiconductor laser capable of producing a high optical output has a coating film applied to an exit end. The coating film has a refractive index (n1) which is large compared with the refractive index (neff) of a semiconductor waveguide. The refractive index (n1) and the refractive index (neff) satisfy the relationship: n12>neff.

Abstract: A small-size-sheet stacking unit is attached on a printed sheet tray of a printing machine so as to receive printed sheets of small size, and is detached from the printing machine after such sheets are printed. The sheet stacking unit comprises a guide plate, a plurality of carriers for supporting side edges of a printed sheet and moving the printed sheet upward, a position sensor for detecting whether or not the printed sheet is at a position where the sheet is ready to be carried by the carriers, a driver for actuating the carriers, and a sheet receptacle for receiving the printed sheets.