摘要:
In a package mounting an optical semiconductor module, an optical semiconductor module is supported by a supporter fixed on a metallic base such that the optical semiconductor module is inclined relative to the circuit board. Further, a lead pin of the optical semiconductor module is set as high as a signal input/output line of a high frequency circuit board. The lead pin is fixed at the shortest distance to the signal input/output line with solder. Thus, the performance of the optical semiconductor module is not deteriorated, and the other components on the circuit board are not affected. A circuit board may be arranged below the optical semiconductor module.
摘要:
An input impedance matching circuit unit is employed, which is connected between a laser diode chip and a modulation signal input terminal in a module package of a semiconductor laser module that directly modulates micro-wave frequency signals. This input impedance matching circuit unit integrates structural elements such as a micro-strip line, a reactance element, and a bonding wire on a single dielectric surface.
摘要:
In an optical module such as an optical branching and multiplexing device used in an optical communication system, optical waveguides are formed on a surface of an optical waveguide substrate and optical fibers are held by arranging guide grooves on an optical fiber arranging substrate. The optical waveguide substrate has positioning guide grooves which can engage with the arranging guide grooves. The pitch of the optical waveguides on end faces of the optical waveguide substrate coincide with the pitch of the arranging guide grooves, so that the optical fibers and the optical waveguides are coupled accurately without any adjustment.
摘要:
The invention provides a semiconductor laser module with an electronic cooling device prevented from experiencing a lowering of the optical frequency response characteristic level in a band used for public communications. By changing the inductance of the ground line between module package and chip-mounted carrier of the semiconductor laser module, the resonance frequency of a resonance circuit made up by including the ground line is shifted so as to deviate from the frequency band of public communications used by a modulation signal transmitting device.
摘要:
In an optical module such as an optical branching and multiplexing device used in an optical communication system, optical waveguides are formed on a surface of an optical waveguide substrate and optical fibers are held by arranging guide grooves on an optical fiber arranging substrate. The optical waveguide substrate has positioning guide grooves which can engage with the arranging guide grooves. The pitch of the optical waveguides on end faces of the optical waveguide substrate coincide with the pitch of the arranging guide grooves, so that the optical fibers and the optical waveguides are coupled accurately without any adjustment.
摘要:
A first substrate on which an optical-waveguide groove is formed and a second substrate. The second substrate is bonded to the plane of the first substrate on which the optical-waveguide groove is formed by a material having a refractive index higher than those of the first substrate and second substrate. The optical-waveguide groove is filled with the material, and the refractive index of the first substrate is different from the refractive index of the second substrate.
摘要:
The apparatus has: a wavelength tunable filter 1; a photoelectric conversion part 2 which converts transmitted light received from the wavelength tunable filter 1 into a received light intensity signal; a received light intensity detecting part 3 which detects the intensity of the received light intensity signal; a signal component detecting part 8 which detects a signal component from the received light intensity signal; a signal intensity detecting part 9 which detects the intensity of the signal component; an intensity variation detecting part 4 which detects an intensity variation in the received light intensity signal which is detected and an intensity variation in the signal component; and a peak position detecting part 5 and a wavelength scanning part 6 which scan and a wavelength to be selected by the wavelength tunable filter 1 based on the two detected variations.
摘要:
An input light beam is applied to a diffraction element. The diffraction element is moved relative to a path of the input light beam while the input light beam is diffracted by the diffraction element and is thereby made into a diffracted light beam traveling from the diffraction element. A portion of the diffracted light beam is detected, and an intensity of the received diffracted light beam is also detected. In addition, a peak of the detected intensity of the received diffracted light beam is detected while the diffraction element is moved relative to the path of the input light beam. A position of the diffraction element is detected at which the detected peak of the detected intensity occurs. The position of the diffraction element is controlled on the basis of the detected position at which the detected peak of the detected intensity occurs.
摘要:
A transmitting circuit apparatus has a frequency modulator that performs frequency modulation of a carrier wave with frequency modulation data and outputs the frequency-modulated carrier wave; a sigma-delta modulator which performs sigma delta modulation of amplitude modulation data; and an amplitude modulator that performs amplitude modulation of the frequency-modulated carrier wave with an output signal of the sigma-delta modulator and outputs the amplitude-modulated carrier wave.
摘要:
A transmitting circuit apparatus has a first digital modulator and a second digital modulator for modulating an I signal and a Q signal which are multi-valued digital baseband modulation signals, into a digital I signal and a digital Q signal, respectively, having the number of bits smaller than that of the baseband modulation signals; and a quadrature modulator for outputting a signal synthesized from the signals generated by modulating (two) carrier waves each having a phase perpendicular to each other by using the modulated I and Q signals, respectively.