Abstract: An optical multiplexing/demultiplexing device comprise a plurality of propagation waveguides comprising an input waveguide capable of receiving input light and an output waveguide outputting light of a given wavelength among the wavelengths included in the input light and resonance waveguide that is an optical waveguide provided between adjoining waveguides and extends in a longitudinal direction in which both the adjoining waveguides extend, wherein the adjoining waveguides are an adjoining pair among the propagation waveguides. The distance between the resonance waveguide and each of the adjoining waveguides of the resonance waveguide and a length in the longitudinal direction of the resonance waveguide are set so as to form a transition part, wherein when a light comprising a transition wavelength set to the transition part passes through the transition part of one of the adjoining waveguides, the light of the transition wavelength component shifts to the other adjoining propagation waveguide.

Abstract: An optical receiver is provided with a photoelectric converter that outputs an electrical signal according to light that is received by a light-receiving region. The optical receiver is provided with a condensing lens and optical filter that are located in an optical path from where signal light enters towards the light-receiving region. The condensing lens condenses the signal light onto the light-receiving region. The optical filter reflects light having a first wavelength that is included in the signal light using a front surface thereof and reflects light having a second wavelength that is included in the signal light using a rear surface thereof that faces the front surface so that the light is emitted through the front surface.

Abstract: A method of manufacturing an optical apparatus having an optical element, a holding member, and a base member includes preparing the holding member and fixing the optical element to the first member. The method further includes fixing a second member of the holding member to the base member and plastically deforming a first member of the holding member and the second member to adjust the position of the optical element.

Abstract: To make miniaturization of a laser module easier. In the laser block of a laser module, multiple semiconductor laser elements that each emit a beam of laser light are disposed. A collimating lens receives and collimates the individual beams of laser light emitted from the laser block, and emits collimated light. Photodiodes detect the individual beams of collimated light emitted from the collimating lens, and output signals corresponding to the intensities of the individual beams of collimated light. Additionally, the photodiodes are disposed on the propagation paths of collimated light emitted from the collimating lens, and in addition, are disposed at positions that receive a portion of collimated light for all the individual beams of collimated light which are emitted.

Abstract: Multiple optical semiconductor devices each outputs light beam corresponding to electric signals. A Peltier element is so provided as to be able to cool the multiple optical semiconductor devices. Resistors are so provided near the optical semiconductor devices as to be able to transfer to one of the optical semiconductor devices heat they produce when energized.

Abstract: In a wavelength monitor that monitors a wavelength of laser light emitted from at least two semiconductor lasers formed in parallel on a semiconductor substrate, the wavelength monitor includes a collimating lens that collimates laser light from each of the semiconductor lasers, an etalon that is arranged so that laser light collimated by the collimating lens is capable of entering and has a periodicity, and a photodetector that receives laser light transmitted through the etalon and detects a light intensity, wherein a beam propagation angle in the etalon of laser light emitted from each of the semiconductor lasers becomes a predetermined angle obtained by formula 1.

Abstract: Included are a first modulator, a second modulator, a first optical amplifier that amplifies an output of the first modulator at an amplification factor based on a first bias signal, a second optical amplifier that amplifies an output of the second modulator at an amplification factor based on a second bias signal, an optical phase adjuster that phase-rotates an output of the second optical amplifier, an optical multiplexer that multiplexes an output of the first optical amplifier with an output of the optical phase adjuster, and a second bias corrector that generates a first pulse signal and a second pulse signal, which are complementary to each other, and obtains a first bias value and a second bias value based on a change of strength of an output signal of the optical multiplexer. The first and second pulse signals are superimposed on the first and second bias signals, respectively.

Abstract: An optical modulator includes first and second modulation waveguides, a demultiplexer, first and second phase adjustment waveguides that changes phases of a light of the first and second modulation waveguides, a multiplexer that combines light outputs from the first and second phase adjustment waveguides, a gain controller and a modulator bias controller in which voltages of the first and second modulation signals are controlled so that a result of adding light from the first modulation waveguide to light from the second modulation waveguide where light from the first modulation waveguide has a predetermined phase is equal to a result of adding light from the first modulation waveguide to light from the second modulation waveguide where light from the second modulation waveguide has a predetermined phase. A phase-adjustment bias controller that controls phase amounts changed by the first and second phase adjustment waveguides so as to cancel phase errors.

Abstract: In a wavelength monitor that monitors a wavelength of laser light emitted from at least two semiconductor lasers formed in parallel on a semiconductor substrate, the wavelength monitor includes a collimating lens that collimates laser light from each of the semiconductor lasers, an etalon that is arranged so that laser light collimated by the collimating lens is capable of entering and has a periodicity, and a photodetector that receives laser light transmitted through the etalon and detects a light intensity, wherein a beam propagation angle in the etalon of laser light emitted from each of the semiconductor lasers becomes a predetermined angle obtained by formula 1.

Abstract: A two-dimensional photonic crystal according to the present invention includes a first layer having a dielectric first layer slab in which first layer holes having a refractive index lower than that of the first layer slab are arranged cyclically, a second layer formed on the first layer, including dielectric columns having a refractive index higher than the air arranged in the air with the same cycle as the first layer hole, and a third layer having a dielectric third layer slab in which third layer holes having a refractive index lower than that of the third layer slab are arranged cyclically. Thus, it is possible to obtain the two-dimensional photonic crystal that can create a wider complete PBG than before regardless of the polarization of light and can be manufactured easily.

Abstract: A multiple wavelength light detector module includes an optical fiber emitting an optical signal including light of multiple wavelengths, a prism on which the optical signal is incident, a total reflection mirror bonded to a first surface of the prism, a bandpass filter bonded to a second surface of the prism, opposite the first surface, and a photodetector for detecting optical beams exiting the bandpass filter. The first surface extends at an angle with respect to the second surface. When light is incident on the bandpass filter, the bandpass filter transmits only light of a particular wavelength determined by the angle of incidence of the light, and reflects light of remaining wavelengths in the light.

Abstract: Included are a first modulator, a second modulator, a first optical amplifier that amplifies an output of the first modulator at an amplification factor based on a first bias signal, a second optical amplifier that amplifies an output of the second modulator at an amplification factor based on a second bias signal, an optical phase adjuster that phase-rotates an output of the second optical amplifier, an optical multiplexer that multiplexes an output of the first optical amplifier with an output of the optical phase adjuster, and a second bias corrector that generates a first pulse signal and a second pulse signal, which are complementary to each other, and obtains a first bias value and a second bias value based on a change of strength of an output signal of the optical multiplexer. The first and second pulse signals are superimposed on the first and second bias signals, respectively.

Abstract: A two-dimensional photonic crystal according to the present invention includes a first layer having a dielectric first layer slab in which first layer holes having a refractive index lower than that of the first layer slab are arranged cyclically, a second layer formed on the first layer, including dielectric columns having a refractive index higher than the air arranged in the air with the same cycle as the first layer hole, and a third layer having a dielectric third layer slab in which third layer holes having a refractive index lower than that of the third layer slab are arranged cyclically. Thus, it is possible to obtain the two-dimensional photonic crystal that can create a wider complete PBG than before regardless of the polarization of light and can be manufactured easily.