Abstract: The obstacle detection apparatus mainly includes an optical deflector, a first reflection mirror, a second reflection mirror, and a light receiver. The first reflection mirror is arranged to face the optical deflector. The second reflection mirror is arranged at one side of the first reflection mirror further from the optical deflector. The optical deflector scans a light beam conically about a first axis. The first reflection mirror and the second reflection mirror are driven to rotate about a second axis in synchronization with each other. The second axis is coaxial with the first axis.

Abstract: An optical semiconductor device includes a semiconductor substrate, a first semiconductor layer provided on the semiconductor substrate, and a mesa waveguide provided on the principal surface of the first semiconductor layer. The semiconductor device also includes a buried layer covering the upper surface of the first semiconductor layer. Part of the upper surface of the first semiconductor layer is exposed. A mesa structure provided at the boundary between a part of the first semiconductor layer is covered with the buried layer and a part of the first semiconductor layer is exposed. One side of the mesa structure is covered with the buried layer, and the other side is exposed. The optical semiconductor device can reduce the generation of stress in the buried layer, for example, to suppress the occurrence of cracks in the buried layer and enhance the reliability.

Abstract: The optical scanning device includes: a movable portion having a reflecting mirror; an intermediate frame; a support portion enclosing the intermediate frame; a first torsion bar connecting the movable portion and the intermediate frame to each other; a second torsion bar connecting the intermediate frame and the support portion to each other; a first wire formed on the movable portion; a second wire formed on the intermediate frame; a magnet; a first drive waveform generation unit configured to supply a first drive signal to the first wire; a second drive waveform generation unit configured to supply a second drive signal to the second wire; and a correction signal generation unit configured to generate a correction signal by shifting a phase of the branch-off first drive signal and multiplying an amplitude of the branch-off first drive signal by a gain, and superimpose the correction signal on the second drive signal.

Abstract: The present invention includes a step for depositing an active layer, a cladding layer, and a contact layer on a semiconductor substrate, a step for etching the layers to form a mesa structure, a step for forming an insulation film to cover the mesa structure, a step for reducing the thickness of the insulation film until the top surface of the contact layer is exposed and using the remaining insulation film as a side wall, a step for forming a dielectric resin layer and burying the mesa structure and the side wall, a step for selectively etching the dielectric resin layer to form an opening and causing the top surface of the contact layer to be exposed, and a step for forming an electrode in the opening.

Abstract: An optical semiconductor device includes a semiconductor substrate, a first semiconductor layer provided on the semiconductor substrate, and a mesa waveguide provided on the principal surface of the first semiconductor layer. The semiconductor device also includes a buried layer covering the upper surface of the first semiconductor layer. Part of the upper surface of the first semiconductor layer is exposed. A mesa structure provided at the boundary between a part of the first semiconductor layer is covered with the buried layer and a part of the first semiconductor layer is exposed. One side of the mesa structure is covered with the buried layer, and the other side is exposed. The optical semiconductor device can reduce the generation of stress in the buried layer, for example, to suppress the occurrence of cracks in the buried layer and enhance the reliability.

Abstract: An optical modulator element includes first and second optical modulators, an optical input terminal, and a branch coupler. Each of the first and second optical modulators includes a pair of Mach-Zehnder waveguides, a first optical coupler to split rays from the branch coupler into the pair of Mach-Zehnder waveguides, and a second optical coupler to combine rays transmitted through the pair of Mach-Zehnder waveguides. The first and second optical modulators are disposed in such a manner that a traveling direction of rays propagating through the pair of Mach-Zehnder waveguides of the first optical modulator and a traveling direction of rays propagating through the pair of Mach-Zehnder waveguides of the second optical modulator are angled toward each other.

Abstract: An optical modulator element includes first and second optical modulators, an optical input terminal, and a branch coupler. Each of the first and second optical modulators includes a pair of Mach-Zehnder waveguides, a first optical coupler to split rays from the branch coupler into the pair of Mach-Zehnder waveguides, and a second optical coupler to combine rays transmitted through the pair of Mach-Zehnder waveguides. The first and second optical modulators are disposed in such a manner that a traveling direction of rays propagating through the pair of Mach-Zehnder waveguides of the first optical modulator and a traveling direction of rays propagating through the pair of Mach-Zehnder waveguides of the second optical modulator are angled toward each other.

Abstract: A first arm portion and a second arm portion are provided so as to have a distance therebetween greater than a distance between input ends of two output waveguides and greater than a distance between an output end of a first output portion and an output end of a second output portion, the first arm portion forming a traveling path of light from one of the two output waveguides to the first output portion through a first optical amplifier, the second arm portion forming a traveling path of light from another one of the two output waveguides to the second output portion through a second optical amplifier. The first optical amplifier and the second optical amplifier have curved portions in which the first output portion and the second output portion are curved in a direction toward each other, and the first optical amplifier and the second optical amplifier respectively output light from the output end of the first output portion and the output end of the second output portion.

Abstract: A first arm portion and a second arm portion are provided so as to have a distance therebetween greater than a distance between input ends of two output waveguides and greater than a distance between an output end of a first output portion and an output end of a second output portion, the first arm portion forming a traveling path of light from one of the two output waveguides to the first output portion through a first optical amplifier, the second arm portion forming a traveling path of light from another one of the two output waveguides to the second output portion through a second optical amplifier. The first optical amplifier and the second optical amplifier have curved portions in which the first output portion and the second output portion are curved in a direction toward each other, and the first optical amplifier and the second optical amplifier respectively output light from the output end of the first output portion and the output end of the second output portion.

Abstract: A system for measuring a linewidth of an optical signal includes an optical sensor determining a set of measurements of the linewidth of the optical signal propagated over different distances. Each measurement corresponds to a different distance, and includes a white frequency modulation (FM) noise and a low frequency FM noise. The system also includes a processor for determining values of the white FM noise and the LF FM noise reducing a difference between the measurements and values of the linewidth of the optical signal calculated for the different distances with the values of the white FM noise and the LF FM noise.

Abstract: A system for measuring a linewidth of an optical signal includes an optical sensor determining a set of measurements of the linewidth of the optical signal propagated over different distances. Each measurement corresponds to a different distance, and includes a white frequency modulation (FM) noise and a low frequency FM noise. The system also includes a processor for determining values of the white FM noise and the LF FM noise reducing a difference between the measurements and values of the linewidth of the optical signal calculated for the different distances with the values of the white FM noise and the LF FM noise.

Abstract: An element carrier has a mounting surface where at least one element outputting a high-frequency signal is disposed. A first dielectric layer has a first side surface partially forming the mounting surface and a first main surface connecting to the first side surface and extending in an intersecting direction intersecting with the mounting surface. A first wiring pattern is provided on the first main surface and extends from the first side surface. A second dielectric layer has a second side surface partially forming the mounting surface and a second main surface connecting to the second side surface and extending in the intersecting direction, and is provided on a part of the first main surface of the first dielectric layer where the first wiring pattern is provided. A second wiring pattern is provided on the second main surface of the second dielectric layer and extends from the second side surface.