Abstract: An optical fiber sensor device includes a control section configured to compute a physical quantity in an optical fiber installed at plural measurement locations based on intensity of scattered light received, and to compute an average of the computed physical quantity for the optical fiber. The control section is configured to compute the average of the physical quantity based on the computed physical quantity and on a length of the optical fiber. A length of the optical fiber installed at the measurement location is increased as a distance between a light source and the respective measurement location increases.

Abstract: An optical fiber sensor device includes a control section configured to compute a physical quantity in an optical fiber installed at plural measurement locations based on intensity of scattered light received, and to compute an average of the computed physical quantity for the optical fiber. The control section is configured to compute the average of the physical quantity based on the computed physical quantity and on a length of the optical fiber. A length of the optical fiber installed at the measurement location is increased as a distance between a light source and the respective measurement location increases.

Abstract: Object is to enable a directly-modulated semiconductor laser to be applied as a light source of probe light. A transmission unit configured to generate probe light; and a reception unit including a receiver-side optical bandpass filter that extracts a Stokes component of Brillouin backscattered light from backscattered light which is caused by the probe light in a measurement target optical fiber, and a self-delayed heterodyne interferometer that detects a change in a frequency shift amount of the Stokes component as a phase difference are included. The transmission unit includes a directly-modulated light source configured to generate an optical pulse, and a transmitter-side optical bandpass filter provided in a stage following the directly-modulated light source, and configured to transmit wavelength of an ON level of the optical pulse as the probe light, and block wavelength of an OFF level.

Abstract: Object is to enable a directly-modulated semiconductor laser to be applied as a light source of probe light. A transmission unit configured to generate probe light; and a reception unit including a receiver-side optical bandpass filter that extracts a Stokes component of Brillouin backscattered light from backscattered light which is caused by the probe light in a measurement target optical fiber, and a self-delayed heterodyne interferometer that detects a change in a frequency shift amount of the Stokes component as a phase difference are included. The transmission unit includes a directly-modulated light source configured to generate an optical pulse, and a transmitter-side optical bandpass filter provided in a stage following the directly-modulated light source, and configured to transmit wavelength of an ON level of the optical pulse as the probe light, and block wavelength of an OFF level.

Abstract: By removing remaining components of Rayleigh scattered light, control is sufficiently performed of polarization states even when the wavelength of scattered light has changed. A light source unit configured to generate probe light, a wavelength control unit configured to receive backscattered light emitted from an optical fiber to be tested by the probe light and to output Brillouin backscattered light included in the backscattered light, and a self-delayed heterodyne interferometer to which the Brillouin backscattered light is input are included. The wavelength control unit includes a wavelength separation filter, a variable wavelength filter, an optical intensity measurement unit, and a control unit. The wavelength separation filter has two output ports, outputs and transmits, from one of the two output ports, the Brillouin backscattered light to the variable wavelength filter, and outputs and transmits, from the other output port, Rayleigh scattered light to the optical intensity measurement unit.

Abstract: By removing remaining components of Rayleigh scattered light, control is sufficiently performed of polarization states even when the wavelength of scattered light has changed. A light source unit configured to generate probe light, a wavelength control unit configured to receive backscattered light emitted from an optical fiber to be tested by the probe light and to output Brillouin backscattered light included in the backscattered light, and a self-delayed heterodyne interferometer to which the Brillouin backscattered light is input are included. The wavelength control unit includes a wavelength separation filter, a variable wavelength filter, an optical intensity measurement unit, and a control unit. The wavelength separation filter has two output ports, outputs and transmits, from one of the two output ports, the Brillouin backscattered light to the variable wavelength filter, and outputs and transmits, from the other output port, Rayleigh scattered light to the optical intensity measurement unit.

Abstract: There is provided an apparatus allowing waveform shaping even at a low sampling rate, which includes a sampling unit, an equalizing unit, a tap coefficient calculating unit, a delay adjusting unit, a peak monitoring unit, and a timing value extracting unit. The timing value extracting unit provides a magnitude of a delay to the delay adjusting unit, and from a plurality of sets of the magnitude of the delay provided by the delay adjusting unit and maximum values of output signal intensity acquired by the peak monitoring unit, acquires the magnitude of a delay where the output signal intensity becomes the greatest, as a suitable delay amount, and notifies the delay adjusting unit of the suitable delay amount.

Abstract: There is provided an apparatus allowing waveform shaping even at a low sampling rate, and including a sampling unit 20, an equalizing unit 30, a tap coefficient calculating unit 40, a delay adjusting unit 80, a peak monitoring unit 60, and a timing value extracting unit 70. The timing value extracting unit 70 instructs magnitude of a delay to the delay adjusting unit, and from a plurality of sets of the magnitude of the delay given by the delay adjusting unit and maximum values of output signal intensity acquired by the peak monitoring unit, acquires the magnitude of a delay where the maximum value of the output signal intensity becomes maximum, as a delay suitable amount, and notifies the delay adjusting unit of the delay suitable amount.

Abstract: Conventional semiconductor devices have a problem that it is difficult to prevent the short circuit between chips and to improve accuracy in temperature detection with the controlling semiconductor chips. In a semiconductor device of the present invention, a first mount region to which a driving semiconductor chip is fixedly attached and a second mount region to which a controlling semiconductor chip is fixedly attached are formed isolated from each other. A projecting area is formed in the first mount region, and the projecting area protrudes into the second mount region. The controlling semiconductor chip is fixedly attached to the top surfaces of the projecting area and the second mount region by use of an insulating adhesive sheet material. This structure prevents the short circuit between the two chips, and improves accuracy in temperature detection with the controlling semiconductor chip.

Abstract: An optical repeater formed in an optical passive component passively relays an incoming multiplexed optical signal. The repeater has an optical decoder decoding the multiplexed optical signal, and an optical encoder encoding an optical signal from a termination unit connected to the repeater. The repeater further includes a first optical path switch outputting an incoming multiplexed optical signal to the optical decoder and outputting the optical signal delivered from the optical decoder, a second optical path switch outputting the optical signal coming from the first optical path switch to the termination unit, and a third optical path switch outputting the optical signal coming from the second optical path switch to the encoder and outputting the optical signal delivered from the encoder.

Abstract: Conventional semiconductor devices have a problem that it is difficult to prevent the short circuit between chips and to improve accuracy in temperature detection with the controlling semiconductor chips. In a semiconductor device of the present invention, a first mount region to which a driving semiconductor chip is fixedly attached and a second mount region to which a controlling semiconductor chip is fixedly attached are formed isolated from each other. A projecting area is formed in the first mount region, and the projecting area protrudes into the second mount region. The controlling semiconductor chip is fixedly attached to the top surfaces of the projecting area and the second mount region by use of an insulating adhesive sheet material. This structure prevents the short circuit between the two chips, and improves accuracy in temperature detection with the controlling semiconductor chip.

Abstract: Conventional semiconductor devices have a problem that it is difficult to prevent the short circuit between chips and to improve accuracy in temperature detection with the controlling semiconductor chips. In a semiconductor device of the present invention, a first mount region to which a driving semiconductor chip is fixedly attached and a second mount region to which a controlling semiconductor chip is fixedly attached are formed isolated from each other. A projecting area is formed in the first mount region, and the projecting area protrudes into the second mount region. The controlling semiconductor chip is fixedly attached to the top surfaces of the projecting area and the second mount region by use of an insulating adhesive sheet material. This structure prevents the short circuit between the two chips, and improves accuracy in temperature detection with the controlling semiconductor chip.

Abstract: An optical repeater formed in an optical passive component passively relays an incoming multiplexed optical signal. The repeater has an optical decoder decoding the multiplexed optical signal, and an optical encoder encoding an optical signal from a termination unit connected to the repeater. The repeater further includes a first optical path switch outputting an incoming multiplexed optical signal to the optical decoder and outputting the optical signal delivered from the optical decoder, a second optical path switch outputting the optical signal coming from the first optical path switch to the termination unit, and a third optical path switch outputting the optical signal coming from the second optical path switch to the encoder and outputting the optical signal delivered from the encoder.

Abstract: A parallel decoder for decoding a code division multiplexed (CDM) signal. The parallel decoder has two matched filters, both operating at a frequency equal to half the chip rate of the CDM signal. One matched filter correlates odd-numbered chips of the CDM signal with odd-numbered chips of the spreading code. The other matched filter correlates even-numbered chips of the CDM signal with even-numbered chips of the spreading code. The two resulting correlated signals are combined, and the decoded signal is obtained from the combined signal. This arrangement doubles the maximum possible chip rate of the CDM signal.

Abstract: The present invention provides a method of generating time-division multiplexed encoded transmission signals, including encoding optical pulse signals for each of a plural multiplexed channels and generating a transmission signal for each channel, performing time division multiplexing on first and second transmission signals and generating a 2-channel multiplexed signal modulating the multiplexed signal with a modulation signal having a frequency of (F??f) Hz, detecting a strength of a ?f Hz frequency component of the multiplexed signal changing a time delay amount of the second transmission signal with respect to the first transmission signal, and determining a time delay amount at which a strength of the ?f Hz frequency component is minimized and adjusting the transmission signals of the individual channels such that they are arranged at equidistant intervals on a time axis.

Abstract: An optical access network system capable of transmitting and receiving high-speed signals and which allows the number of subscribers to be increased without increasing the number of wavelengths used is provided. An optical line terminal and an optical network unit are joined via an optical fiber transmitting line, a star coupler, and a plurality of branching optical fiber transmitting lines. The optical line terminal and optical network unit are constituted comprising an optical processing section and an electrical processing section. The optical processing section comprises a light-emitting element and a light-receiving element.

Abstract: The present invention provides a method of generating time-division multiplexed encoded transmission signals, including encoding optical pulse signals for each of a plural multiplexed channels and generating a transmission signal for each channel, performing time division multiplexing on first and second transmission signals and generating a 2-channel multiplexed signal modulating the multiplexed signal with a modulation signal having a frequency of (F??f) Hz, detecting a strength of a ?f Hz frequency component of the multiplexed signal changing a time delay amount of the second transmission signal with respect to the first transmission signal, and determining a time delay amount at which a strength of the ?f Hz frequency component is minimized and adjusting the transmission signals of the individual channels such that they are arranged at equidistant intervals on a time axis.

Abstract: Technology is provided in which, by performing time gate processing using a clock signal with time jitter suppressed, time and intensity fluctuations which in the prior art had been observed in auto-correlated signals after time gate processing are reduced. In a decoder, received optical code division multiplexed signals are divided into two, one of which is reflected as a decoded signal, and the other of which is transmitted as an encoded signal in the encoded state. In the clock extraction circuit, encoded signals are divided into first encoded signals and second encoded signals. In the first clock signal generation portion, first clock signals are generated from the first encoded signals, and optical pulses synchronized with the first clock signals are extracted from the second encoded signals, and second clock signals are generated from the extracted optical pulses.

Abstract: An object of the present invention is to provide an OCDM transceiver with which the reduction amount of the intensity of the correlation waveform signal is smaller than that of a conventional device of the same type in the decoding step that comprises a time gate processing step. Hence, in the OCDM transceiver of the present invention that comprises an encoding portion and a decoding portion, the decoding portion is constituted comprising a decoder, clock extractor, and time gate. The decoder decodes an encoded optical pulse signal and separates the encoded optical pulse signal into a clock signal extraction signal and an optical pulse signal playback signal. The clock extractor extracts a clock signal from the clock signal extraction signal. Further, the time gate removes only the auto-correlation waveform component from the optical pulse signal playback signal. The auto-correlation waveform component is converted to an electrical signal by means of an optical receiver and generated as a reception signal.

Abstract: A parallel decoder for decoding a code division multiplexed (CDM) signal. The parallel decoder has two matched filters, both operating at a frequency equal to half the chip rate of the CDM signal. One matched filter correlates odd-numbered chips of the CDM signal with odd-numbered chips of the spreading code. The other matched filter correlates even-numbered chips of the CDM signal with even-numbered chips of the spreading code. The two resulting correlated signals are combined, and the decoded signal is obtained from the combined signal. This arrangement doubles the maximum possible chip rate of the CDM signal.