Abstract: A wavelength-multiplexed light transmission module according to the present invention includes a plurality of lasers that respectively emit a plurality of laser beams having different wavelengths, a lens radially emitting the plurality of laser beams, a bandpass filter that has a transmission center wavelength which is shorter as an incident angle is larger, and a mirror for reflecting the plurality of laser beams, wherein the plurality of laser beams are incident to the bandpass filter such that the incident angle of a laser beam is larger as the laser beam has a shorter wavelength, whereby the plurality of laser beams are transmitted through the bandpass filter, and an inclination angle of the mirror with respect to the bandpass filter is provided such that the plurality of laser beams transmitted through the bandpass filter are reflected by the bandpass filter and the mirror to be multiplexed with one another.

Abstract: A wavelength-multiplexed light transmission module according to the present invention includes a plurality of lasers that respectively emit a plurality of laser beams having different wavelengths, a lens radially emitting the plurality of laser beams, a bandpass filter that has a transmission center wavelength which is shorter as an incident angle is larger, and a mirror for reflecting the plurality of laser beams, wherein the plurality of laser beams are incident to the bandpass filter such that the incident angle of a laser beam is larger as the laser beam has a shorter wavelength, whereby the plurality of laser beams are transmitted through the bandpass filter, and an inclination angle of the mirror with respect to the bandpass filter is provided such that the plurality of laser beams transmitted through the bandpass filter are reflected by the bandpass filter and the mirror to be multiplexed with one another.

Abstract: An optical module includes: a pedestal; a glass optical multiplexer/demultiplexer fixed onto the pedestal via a UV adhesive; and a metal block which is smaller than the glass optical multiplexer/demultiplexer and is fixed to a top surface of the glass optical multiplexer/demultiplexer.

Abstract: An optical module includes: a pedestal; a glass optical multiplexer/demultiplexer fixed onto the pedestal via a UV adhesive; and a metal block which is smaller than the glass optical multiplexer/demultiplexer and is fixed to a top surface of the glass optical multiplexer/demultiplexer.

Abstract: An optical modulator includes: laser diodes disposed in parallel with each other, each laser diode having a different lasing wavelength; optical waveguides disposed in parallel with each other with first ends facing the laser diodes; an optical isolator inserted between the laser diodes and the optical waveguides and attenuating return light reflected from the optical waveguides toward the laser diodes; a lens focusing light emitted from the laser diodes onto the optical waveguides through the optical isolator; an optical switch selecting one of the light beams exiting from the optical waveguides; and an optical modulator modulating the light beam selected by and output from the optical switch.

Abstract: An optical detector module includes a carrier, a photodetector secured to a top surface of the carrier and having a light detecting portion, an anode terminal, and a cathode terminal, an amplifier circuit secured to the top surface of the carrier and having a first edge, an input terminal, and a GND terminal. The input terminal and the GND terminal are located along the first edge. A first wire connects the anode terminal to the input terminal, and to a composite component secured to the top surface of the carrier and having a metal portion and a resistive portion integrated together. The metal portion is in contact with the carrier. A capacitor, having a top surface electrode and a bottom surface electrode is secured to the carrier.

Abstract: An optical detector module includes a carrier, a photodetector secured to a top surface of the carrier and having a light detecting portion, an anode terminal, and a cathode terminal, an amplifier circuit secured to the top surface of the carrier and having a first edge, an input terminal, and a GND terminal. The input terminal and the GND terminal are located along the first edge. A first wire connects the anode terminal to the input terminal, and to a composite component secured to the top surface of the carrier and having a metal portion and a resistive portion integrated together. The metal portion is in contact with the carrier. A capacitor, having a top surface electrode and a bottom surface electrode is secured to the carrier.

Abstract: An optical modulator includes: laser diodes disposed in parallel with each other, each laser diode having a different lasing wavelength; optical waveguides disposed in parallel with each other with first ends facing the laser diodes; an optical isolator inserted between the laser diodes and the optical waveguides and attenuating return light reflected from the optical waveguides toward the laser diodes; a lens focusing light emitted from the laser diodes onto the optical waveguides through the optical isolator; an optical switch selecting one of the light beams exiting from the optical waveguides; and an optical modulator modulating the light beam selected by and output from the optical switch.

Abstract: An optical transmitter includes an equalizer which receives a data signal, an optical modulator driver which amplifies an output signal of the equalizer, and an optical modulator which converts an output signal of the optical modulator driver into an optical signal and outputs the optical signal. The equalizer has a signal line for transmitting the data signal, a coupled line electromagnetically coupled to the signal line, a resistive section connected to the coupled line, and a ground via connected to the resistive section. The equalizer reduces power of the data signal in a frequency range where the frequency response characteristic of the optical modulator driver exhibits peaking, to reduce waveform jitter in the output signal of the optical modulator driver that is input to the optical modulator.

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: A semiconductor optical modulation device includes a semiconductor optical modulator, wires, an output side line, an input side line and a resistor. The semiconductor optical modulator is an electroabsorption optical modulator. One of the wires is connected between an electrode of the semiconductor optical modulator and the input side line. The other of the wires is connected between the electrode of the semiconductor optical modulator and the output side line. The resistor is connected in series with the output side line. Impedance of the output side line and impedance of the resistor are different from each other.

Abstract: A semiconductor optical modulation device includes a semiconductor optical modulator, wires, an output side line, an input side line and a resistor. The semiconductor optical modulator is an electroabsorption optical modulator. One of the wires is connected between an electrode of the semiconductor optical modulator and the input side line. The other of the wires is connected between the electrode of the semiconductor optical modulator and the output side line. The resistor is connected in series with the output side line. Impedance of the output side line and impedance of the resistor are different from each other.

Abstract: An optical module includes an optical waveguide member for passing light therethrough and an optical path changing member for receiving and reflecting light. The optical path changing member is optically coupled to the optical waveguide member. The optical module further includes a lens optically coupled to the optical path changing member. The optical module further includes a first optical device and a second optical device. The first optical device and the second optical device are disposed to face the optical path changing member through the lens and optically coupled to the lens. The optical path changing member has a first face and a second face at different locations. The first face reflects a first wavelength of light transmitted between the optical waveguide member and the first optical device. The second face reflects a second wavelength of light transmitted between the optical waveguide member and the second optical device.

Abstract: An optical delay circuit includes a plurality of defect waveguides arranged in parallel and including a line-shaped defect in a periodic refractive-index distribution structure of a photonic crystal. The defect waveguides include a multiplexing/demultiplexing portion in which the defect waveguides are arranged close to each other to multiplex and demultiplex light; and an optical delay portion extending from the multiplexing/demultiplexing portion, in which the defect waveguides are arranged with a predetermined distance therebetween so that light propagating in any of the defect waveguides does not interfere with light propagating in the other defect waveguides. Each of the waveguides has a different configuration.

Abstract: A semiconductor laser device includes an optical fiber having an optical fiber grating formed therein, a semiconductor laser having an active layer with a single quantum well, for emitting laser light, and a coupling optical system for coupling the laser light emitted out of the semiconductor laser into the optical fiber. The coupling optical system can include a narrow-band filter for adjusting an incident angle of the laser light emitted out of the semiconductor laser. The optical fiber grating can have a reflection bandwidth wider than or substantially equal to a 3dB bandwidth of the gain of the semiconductor laser or a spectrum full width at half maximum of the laser light of the semiconductor laser.

Abstract: A method of manufacturing an optical switch includes forming a starting groove in a first surface of polymer film that includes an internal optical waveguide linearly estending within the polymer film, the starting groove corresponding to a switching portion of the polymer film, and clamping the polymer film with a keep plate having a switching through hole. The polymer film is pressed at a second surface at a starting groove with a pressing member causing cleavage of the polymer film at the starting groove, and forming a notch in said polymer film at the first surface, extending across the switching portion at the starting groove.

Abstract: An optical switch includes a film consisting of a polymer, a keep plate having a switching through hole and a driver. The film has a core linearly extending therein and a notch extending across a switching portion located halfway in the core. The keep plate holds the film to expose the switching portion at the through hole. The driver is employed for narrowing and separating a gap of the notch, thereby selecting a route of light. The notch is formed by precedently forming a starting groove on the surface of the film and pressing the switching portion with a pressing member from the backside of the starting groove while holding the film with the keep plate thereby causing cleavage.

Abstract: A differential drive semiconductor optical modulator includes: a differential driver circuit having output pads which can output a pair of differential signals; a transmission-line substrate having transmission lines connected to the output pads and ground lines; and semiconductor modulators mounted on the transmission-line substrate, arranged in series along a common optical axis; terminal resistors connected to terminal ends of the transmission lines and inductances interposed between the semiconductor modulators and the terminal resistors, on the transmission-line substrate, producing an appropriate optical modulation waveform with a high extinction ratio and enhanced modulation bandwidth.

Abstract: An optical delay circuit includes a plurality of defect waveguides arranged in parallel and including a line-shaped defect in a periodic refractive-index distribution structure of a photonic crystal. The defect waveguides include a multiplexing/demultiplexing portion in which the defect waveguides are arranged close to each other to multiplex and demultiplex light; and an optical delay portion extending from the multiplexing/demultiplexing portion, in which the defect waveguides are arranged with a predetermined distance therebetween so that light propagating in any of the defect waveguides does not interfere with light propagating in the other defect waveguides. Each of the waveguides has a different configuration.

Abstract: An optical switch includes a polymer sheet having an optical waveguide extending linearly therein, keep plates holding the polymer sheet therebetween, and driving means. The polymer sheet has a notch provided to traverse the optical waveguides, and the keep plates each have an opening at a position corresponding to the notch. The opening has an elongated shape along the extending direction of the notch at least on a surface of the keep plate in contact with the polymer sheet. The driving means is for selecting a course of light by switching open and closed states of the notch by pushing and not pushing the polymer sheet via the opening.