Abstract: A signal processing device in an optical sensor device further calculates first frequency variation reference signal data serving as a reference for frequency variation of light output from a wavelength swept light source on the basis of an internal reception signal converted into a digital signal by an analog-to-digital converter, a digital-to-analog converter converts the first frequency variation reference signal data calculated by the signal processing device into an analog signal to generate a first frequency variation reference signal as a first clock signal, and the analog-to-digital converter samples a reception signal acquired by an optical heterodyne receiver in synchronization with the first frequency variation reference signal generated by the digital-to-analog converter.

Abstract: An optical frequency control device includes: a detection circuit to receive first light including a first frequency, receive second light including a second frequency, modulate the first light with a local oscillation signal, and detect a differential beat signal between the frequency of sideband light included in the modulated first light and the second frequency; a light source control circuit to change the second frequency by frequency-dividing the differential beat signal with a first frequency division number, by frequency-dividing a reference signal with a second frequency division number, and by outputting a phase error signal indicating a phase difference between the frequency-divided differential beat signal and the frequency-divided reference signal; and a signal processing unit to set each of the first frequency division number and the second frequency division number according to the set value of a frequency difference between the first frequency and the second frequency.

Abstract: An optical measurement device is a measurement device that measures a distance to a target using light, and includes: a split unit to split light into reference light and measurement light; an adjustment unit to split the reference light into a plurality of beams of reference light having respective different light path lengths; an interference unit to multiplex two of reflection light obtained by reflection when a target is irradiated with the measurement light, and the plurality of beams of reference light to obtain interference light; and a processing unit to calculate a light path length difference on a basis of a frequency of the interference light, and the optical measurement device calculates light path length differences of the plurality of beams of reference light, so that it is possible to measure the distance to the target even when the distance to the target significantly fluctuates.

Abstract: A frequency separator includes a plurality of filters to separate light having a plurality of optical pulses, each of the optical pulses having one of a plurality of frequencies, into a plurality of light components, each of the light components being to have one of a plurality of frequency bands corresponding to the plurality of frequencies, in which among the plurality of filters, a center frequency of a first frequency band of a first filter and a center frequency of a second frequency band, adjacent to the first frequency band, of a second filter are separated beyond a bandwidth of each of the first and second frequency bands.

Abstract: A reception device includes: a first A/D converter to convert the input analog information signal into a first digital information signal by A/D conversion to output it,; an analog amplifier to amplify the input analog information signal to output it; a second A/D converter to convert the analog information amplification signal output from the analog amplifier into a second digital information signal by A/D conversion to output it; a frequency characteristic corrector to output a second digital information correction signal obtained by correcting the second digital information signal output from the second A/D converter based on a frequency-dependent input/output characteristic of the analog amplifier; and an information signal selector and outputter to select and output, as a digital information signal, either the first digital information signal output from the first A/D converter or the second digital information correction signal output from the frequency characteristic corrector.

Abstract: A transmission/reception system includes: a second transmission/reception device configured to convert a multiplexed signal into a first digital signal in a first format, convert the signal into a first analog signal, and convert the signal into a second optical signal, and convert a first electrical signal into a second digital signal, demodulate the signal to generate a third digital signal, and output a plurality of sixth optical signals; and third transmission/reception device configured to convert a second electrical signal into a fourth digital signal, and demodulate the signal to generate a plurality of fifth digital signals; and convert a plurality of sixth digital signals into a seventh digital signal in a second format, convert the signal into a second analog signal, and convert the signal into a fourth optical signal.

Abstract: An optical frequency control device includes: a detection circuit to receive first light including a first frequency, receive second light including a second frequency, modulate the first light with a local oscillation signal, and detect a differential beat signal between the frequency of sideband light included in the modulated first light and the second frequency; a light source control circuit to change the second frequency by frequency-dividing the differential beat signal with a first frequency division number, by frequency-dividing a reference signal with a second frequency division number, and by outputting a phase error signal indicating a phase difference between the frequency-divided differential beat signal and the frequency-divided reference signal; and a signal processing unit to set each of the first frequency division number and the second frequency division number according to the set value of a frequency difference between the first frequency and the second frequency.

Abstract: An optical transmission device includes: a controlled oscillator for outputting a calibration signal having an output frequency that corresponds to an input oscillation control signal; an electrical-to-optical conversion circuit for generating an optical transmission signal by superimposing a transmission signal in a radio frequency band and the calibration signal on an optical wave; an optical input and output unit for sending the optical transmission signal to an optical transmission path and receiving a reflection signal that is a part of the optical transmission signal from an optical reception device; an optical-to-electrical converter for converting the reflection signal into a radio frequency signal; a phase locked loop for generating the oscillation control signal so that radio frequency output of the optical-to-electrical converter is phase-locked with a reference signal input from a reference signal source; and a signal generation circuit for generating, as the transmission signal, the radio frequen

Abstract: An optical transmission device includes: a controlled oscillator for outputting a calibration signal having an output frequency that corresponds to an input oscillation control signal; an electrical-to-optical conversion circuit for generating an optical transmission signal by superimposing a transmission signal in a radio frequency band and the calibration signal on an optical wave; an optical input and output unit for sending the optical transmission signal to an optical transmission path and receiving a reflection signal that is a part of the optical transmission signal from an optical reception device; an optical-to-electrical converter for converting the reflection signal into a radio frequency signal; a phase locked loop for generating the oscillation control signal so that radio frequency output of the optical-to-electrical converter is phase-locked with a reference signal input from a reference signal source; and a signal generation circuit for generating, as the transmission signal, the radio frequen

Abstract: An optical transmitter 1 includes an optical phase modulator 131 that performs phase modulation on a continuously oscillating light, a light intensity modulator 132 that performs pulse modulation on the light on which the phase modulation is performed, to output the light as a transmission light, a first signal generator 133 that generates a pulse modulation driving signal in which on and off time intervals are repeated periodically, to drive the optical intensity modulator 132, and a second signal generator 134 that generates a saw tooth wave driving signal having an amplitude equal to an integral multiple of a driving voltage needed to acquire a modulation phase of 2? of the optical phase modulator 131, and having a constant period, to drive the optical phase modulator 131.

Abstract: A modulation unit 4 is provided which adds, to a frequency ? of transmitted seed light oscillated by a reference light source 2, a frequency (fofs?fmove) resulting from subtracting a Doppler shift frequency fmove corresponding to the moving speed of the moving body from a preset offset frequency fofs, and which outputs pulsed light by performing pulse modulation of the transmitted seed light with a frequency (?+fofs?fmove). An optical heterodyne receiver 8 optically mixes backscattered light with a frequency (?+fofs+fdop) received with an optical antenna 7 and local oscillation light with the frequency ?, thereby obtaining a beat signal with a difference frequency (fofs+fdop) between the backscattered light and the local oscillation light.

Abstract: An optical transmitter 1 includes an optical phase modulator 131 that performs phase modulation on a continuously oscillating light, a light intensity modulator 132 that performs pulse modulation on the light on which the phase modulation is performed, to output the light as a transmission light, a first signal generator 133 that generates a pulse modulation driving signal in which on and off time intervals are repeated periodically, to drive the optical intensity modulator 132, and a second signal generator 134 that generates a saw tooth wave driving signal having an amplitude equal to an integral multiple of a driving voltage needed to acquire a modulation phase of 2? of the optical phase modulator 131, and having a constant period, to drive the optical phase modulator 131.