Abstract: A pad-array arrangement structure on a substrate for mounting an IC chip on the substrate, wherein a structure with which it is possible to maximally avoid an increase in the number of wiring layers on the substrate is obtained by devising the pad arrangement in an IC pad-array region. A embodiment of the present invention provides a pad-array structure on a substrate for mounting an IC chip on the substrate. The present invention is characterized in that: a plurality of ground pads arrayed equidistantly in a first row, and a plurality of signal pads arrayed equidistantly in a second row on the inside of and parallel to the first row, are provided on a first circumferential edge in the pad-array region; each of the signal pads passes between two adjacent ground pads in the first row and is connected to an external circuit on the substrate; and electrical signals are input to and output from the external circuit.

Abstract: A semiconductor integrated circuit that reduces a loss in an electrical signal and a method for manufacturing the semiconductor integrated circuit are provided. The semiconductor integrated circuit comprises a first region on which an optical circuit is to be formed and a second region on which an electrical signal wiring is to be formed. The first region comprises an Si substrate (502), a BOX layer (504) formed on the Si substrate (502), a first SOI layer (506) formed as an optical circuit on the BOX layer (504), and a first SiO2 layer (508) formed on the first SOI layer (506). The second region comprises the Si substrate (502), the BOX layer (504), a second SiO2 layer (508) formed on the BOX layer (504), and an electrical signal wiring (510) formed on the second SiO2 layer (508).

Abstract: There is provided an optical multiplexing and de-multiplexing element which is provided with a slab waveguide and a waveguide structure and can reduce radiation loss caused in a connection part between the slab waveguide and the waveguide structure. The waveguide structure includes a multimode interference (MMI) waveguide coupler and a narrow-width waveguide, the MMI waveguide coupler and the narrow-width waveguide are connected to each other in this order from a connection position with the slab waveguide along the waveguide direction, step portions are formed on both sides of the MMI waveguide coupler along the waveguide direction, and the thickness of the step portion is smaller than the thickness of the MMI waveguide coupler.

Abstract: There is provided a bidirectional optical communication module including a bidirectional optical communication chip configured to include an optical circuit board in which a light receiving element constituting a receiving section, a transmitting element constituting a transmitting section, and a wavelength-division multiplexing (WDM) filter that divides transmission signal light and reception signal light from each other are hybrid-integrated, a reflecting section configured to direct a propagation direction of the transmission signal light output from the transmitting section and the reception signal light received by the receiving section to a direction orthogonal to the optical circuit board, and an optical coupling element configured to spatially optically-couple an input-output port for the transmission signal light and the reception signal light provided at the bidirectional optical communication chip to an input-output port of an optical fiber.

Abstract: According to one embodiment, a semiconductor light-emitting element includes a ring-shaped light-emitting portion provided on a substrate, a mode-control light waveguide of Si provided on an upper or a lower surface side of the light-emitting portion, and including at least two portions located close to the light-emitting portion, and an output light waveguide of Si provided on the upper or the lower surface side, and including a portion located close to the light-emitting portion. The mode-control light waveguide has a structure for coupling light traveling in one of a clockwise circulating mode and a counterclockwise circulating mode, and feeding back the light in the other of the clockwise circulating mode and the counterclockwise circulating mode.

Abstract: A low-cost optical circuit, in which influence of reflected light is reduced, is provided. According to an embodiment of the present invention, an optical circuit (200) comprises a first optical coupler (204A) having at least two outputs, and a second optical coupler (204B) coupled to at least one of the outputs of the first optical coupler (204A), and wherein the ratio of an intensity of light reflected from the first optical coupler (204A) to an intensity of light inputted to the first optical coupler is smaller than the ratio of an intensity of light reflected from the second optical coupler (204B) to an intensity of light inputted to the second optical coupler.

Abstract: A semiconductor light receiving device includes a substrate, a semiconductor fine line waveguide provided on the substrate, and a light receiving circuit that is provided on the substrate and that absorbs light propagating through the semiconductor fine line waveguide. The light receiving circuit includes a p type first semiconductor layer, a number of second semiconductor mesa structures provided on the p type first semiconductor layer in such a manner that an n type second semiconductor layer is provided on top of an i type second semiconductor layer, a p side electrode connected to the p type first semiconductor layer in a location between the second semiconductor mesa structures, and an n side electrode connected to the n type second semiconductor layer. The refractive index and the optical absorption coefficient of the second semiconductor layers are greater than the refractive index and the optical absorption coefficient of the first semiconductor layer.

Abstract: An optical element includes: a polarization splitter that splits light input from an input port into a first signal and a second signal according to a plane of polarization; a polarization rotator that rotates a plane of polarization of the second signal output from the polarization splitter by 90 degrees; a first optical coupler that combines the first signal output from the polarization splitter and the second signal output from the polarization rotator and splits the resultant signal into a third signal and a fourth signal with an equal amplitude; a phase controller that controls a phase of the third signal; and a second optical coupler that combines the third signal output from the phase controller and the fourth signal output from the first optical coupler and splits the resultant signal into a fifth signal and a sixth signal with an equal amplitude.

Abstract: According to one embodiment, a semiconductor light-receiving element, includes a light-receiving part provided on a substrate and having a semiconductor multilayer structure of a circular outer shape, a optical input part formed of a peripheral portion of the semiconductor multilayer structure, and having a tapered front end, and a silicon-thin-line waveguide configured to couple light with the optical input part. The waveguide includes a linear part extending through the optical input part to an at least one area of an upper-side area and a lower-side area of the light-receiving part, and a spiral part connected to the linear part and formed in the at least one area.

Abstract: Provided is a waveguide-type optical diffraction grating. A waveguide core includes a waveguide core that is asymmetric with respect to a thickness direction perpendicular to a light propagating direction. In the waveguide core, a phase adjustment portion is configured to adjust a phase difference between a forward wave traveling in an input direction and a reflected wave traveling in a direction reverse to the input direction in the waveguide-type optical diffraction grating, and the phase adjustment portion is provided in a manner that a sum of a phase of the forward wave and a phase of the reflected wave which are generated in the phase adjustment portion becomes a constant value irrespective of a polarization state of input light to the waveguide-type optical diffraction grating.

Abstract: This present invention is provided with: a semiconductor laser for emitting laser light in a plurality of channels; optical waveguides optically coupled in a corresponding manner to the semiconductor lasers, the optical waveguides propagating laser light as input light for each channel; optical modulators for modulating the input light and generating an optical signal; and an optical signal output unit coupled to the optical modulators, the optical signal output unit outputting the optical signal propagated from the optical modulators to the exterior. The present invention is characterized in that the semiconductor laser is arranged on the opposite side from an optical branching unit and the optical modulators, with the optical signal output unit interposed therebetween, in the plane of an opto-electric hybrid board.

Abstract: An optical element includes: a first delayed interferometer; and a second delayed interferometer and a third delayed interferometer cascaded to the first delayed interferometer. The first delayed interferometer includes: a first optical coupler and a second optical coupler; a first waveguide between the first optical coupler and the second optical coupler; a second waveguide between the first optical coupler and the second optical coupler, the second waveguide being longer than the first waveguide; and a ring waveguide that is coupled to the first waveguide. A difference between a length of the first waveguide and a length of the second waveguide differs from a difference in lengths corresponding to a channel spacing by a length corresponding to a phase displacement caused by loading of the ring waveguide.

Abstract: A photoelectric hybrid device includes an optical connector on a flat optical surface at one end of vertical optical waveguides for inputting and outputting an optical signal. Integration of the photoelectric hybrid device into an interposer or the like is standardized. The photoelectric hybrid device includes: conductive pins connected to an electric signal pathway for a photoelectric hybrid substrate; a translucent member having a flat optical surface and a translucent part; and self-organizing optical waveguides that form an optical path between the translucent part and an optical waveguide. The flat optical surface is not lower than the tops of the electrical connection parts on the conductive pins. Collision of the optical connector and the tops of the electrical connection parts can be avoided when an optical connector on which an optical waveguide that transmits an optical signal among the optical waveguides.

Abstract: A modulated light source includes a ring modulator, a first optical waveguide and a second optical waveguide that are optically connected to the ring modulator, and a third optical waveguide that optically connects an end of the first optical waveguide and an end of the second optical waveguide. At least part of the third optical waveguide has optical gain, and an optical waveguide loop including the ring modulator, the first optical waveguide, the second optical waveguide, and the third optical waveguide is used as a resonator to cause laser oscillation.

Abstract: A modulated light source includes a ring modulator, a first optical waveguide and a second optical waveguide that are optically connected to the ring modulator, and a third optical waveguide that optically connects an end of the first optical waveguide and an end of the second optical waveguide. At least part of the third optical waveguide has optical gain, and an optical waveguide loop including the ring modulator, the first optical waveguide, the second optical waveguide, and the third optical waveguide is used as a resonator to cause laser oscillation.

Abstract: An optical circuit, wherein the effects of reflected light generated by an optical component are reduced. The optical circuit (100) is provided with an optical branching (110) for branching light, an optical coupler (114) for coupling a first portion of branched light to an optical waveguide (118) for transmission, and an optical reflecting unit (116) for reflecting a second portion of the branched light, the phase difference between the reflected light from the optical coupler (114) and the reflected light from the optical reflecting unit (116) being (2m?1)? (where m is an integer) on an input side of the optical branching (110).

Abstract: An object of the present invention is to provide an electro-optical modulator that allows high-speed carrier injection into a silicon-containing i-type amorphous semiconductor, particularly a-Si:H, and has little optical loss. An electro-optical modulator comprises: a substrate 201; an optical waveguide comprising a silicon-containing i-type amorphous semiconductor 204 formed on the substrate; and a silicon-containing p-type semiconductor layer 203 and a silicon-containing n-type semiconductor layer 205 arranged apart from each other with the silicon-containing optical waveguide comprising an i-type amorphous semiconductor 204 interposed therebetween and constituting optical waveguides together with the silicon-containing optical waveguide comprising an i-type amorphous semiconductor. The silicon-containing p-type semiconductor layer 203 and/or silicon-containing n-type semiconductor layer 205 are a crystalline semiconductor layer.

Abstract: There is provided a bidirectional optical communication module including a bidirectional optical communication chip configured to include an optical circuit board in which a light receiving element constituting a receiving section, a transmitting element constituting a transmitting section, and a wavelength-division multiplexing (WDM) filter that divides transmission signal light and reception signal light from each other are hybrid-integrated, a reflecting section configured to direct a propagation direction of the transmission signal light output from the transmitting section and the reception signal light received by the receiving section to a direction orthogonal to the optical circuit board, and an optical coupling element configured to spatially optically-couple an input-output port for the transmission signal light and the reception signal light provided at the bidirectional optical communication chip to an input-output port of an optical fiber.

Abstract: An optical receiving circuit which suppresses a characteristic deterioration due to a wiring between a PD and a TIA and a method for manufacturing the optical receiving circuit are provided. A optical receiving circuit (300) comprises a photodiode (302), and a transimpedance amplifier (308) that supplies an electrical power source to the photodiode (302). The characteristic impedance of a wiring between the anode of the photodiode (302) and the transimpedance amplifier (308) is higher than the characteristic impedance of a wiring between the cathode of the photodiode (302) and the transimpedance amplifier (308).

Abstract: An optical device includes an optical waveguide provided on a principal surface of a substrate. The optical waveguide includes a core and a cladding provided around the core. The cladding is configured by a substance having a refractive index smaller than 71.4% of the refractive index of the core. The core has constituent atoms substantially forming a diamond lattice structure. The optical waveguide has a light input/output part through which a light beam is input and/or output. The light input/output part decreases stepwise in thickness towards an output end while tapering down in its width. The core is provided in the light input/output part to have a (111) plane or an equivalent plane to the (111) plane exposed on a face of a riser of the stepwise thickness of the light input/output part.