Patent application number | Description | Published |
20090086303 | MULTILEVEL OPTICAL PHASE MODULATOR - To take out monitor light unaffected by a multilevel optical phase-modulated component. For the purpose, a phase-shift unit that controls phases of plural (n, n is an integral number equal to or greater than 2) input lights, plural (n, n is an integral number equal to or greater than 2) phase modulating units that respectively phase-modulate the input lights from the phase-shift units, a first coupling unit that couples and outputs the phase-modulated lights from the plural phase modulating units as multilevel optical phase-modulated signal light, and a second coupling unit that couples and outputs non-phase-modulated lights from the plural phase modulating units as coupled light are provided. | 04-02-2009 |
20090141333 | Light modulation device - A light modulation device capable of stabilizing a phase set in phase modulation processing and improving optical communication quality. A phase modulator is provided for each of plural branched input lights and performs phase modulation of the input light. A phase shifter is provided at the upstream or downstream of the phase modulator and shifts a phase of the input light or of the phase-modulated light. A light interference section causes the output lights from the light modulator to interfere with each other to generate a multilevel phase modulated signal and interference light having a phase state different from that of the modulated signal. A monitor receives the interference light and outputs an electric signal according to the intensity. A phase shift controller generates a phase control signal based on the electric signal and applies the signal to the shifter to control the phase shift amount to be set by the shifter. | 06-04-2009 |
20090142074 | OPTICAL RECEIVING APPARATUS, OPTICAL LINE TERMINAL APPARATUS, AND OPTICAL NETWORK SYSTEM - The optical receiving apparatus of the present invention is provided with an optical receiving unit which receives a burst optical signal and outputs a signal in accordance with an optical reception level, a preamplification unit which amplifies the signal from the optical receiving unit, a direct-current component removing unit which removes a direct-current component of a signal output from the preamplification unit and has a variable response time constant, and a time-constant control unit which controls the response time constant of the direct-current component removing unit based on a signal indicating the rising edge of the burst optical signal and a signal indicating the falling edge of the burst optical signal. According to this constitution, the shortening of the rise time and the securing of the tolerance against the same code succession can be simultaneously realized. | 06-04-2009 |
20090175295 | Communication terminal apparatus and signal receiving method - A communication terminal apparatus receives a management signal at a bit rate A and a data signal at a bit rate B (B>A) through the same line, and includes a band limiting unit, a signal regenerating unit, a timing controlling unit, and a data signal obtaining unit. The band limiting unit limits a band. The signal regenerating unit regenerates a signal having the bit rate A or the bit rate B. The timing controlling unit controls timing for obtaining a data signal based on a signal having the bit rate A. The timing controlling unit controls the band limiting unit to limit the band on receipt of the management signal and to lessen band limitation on receipt of the data signal. The data signal obtaining unit obtains the data signal from a signal having the bit rate B according to the timing control. | 07-09-2009 |
20090232519 | OPTICAL RECEIVER FOR REGENERATION OF OPTICAL SIGNAL - An optical receiver includes: a converting unit that converts an optical signal into an electrical signal; an amplifying unit that amplifies the electrical signal; a regenerating unit that regenerates the amplified electrical signal; a correcting unit that performs correction of an error included in the regenerated electrical signal; a monitoring unit that performs monitoring of an optical current flowing through the converting unit; and a control unit that calculates a decision threshold based on a result of the correction and a result of the monitoring. | 09-17-2009 |
20090238582 | Optical receiver - In an optical receiver, a light receiving element receives the optical packet signals and converts the optical packet signals to electrical signals. A bias voltage supply section supplies bias voltage to the light receiving element. A monitoring section monitors an input level of each optical packet signal or each electrical signal and transmits a monitored value to the bias voltage supply section. In addition, the bias voltage supply section temporarily increases the bias voltage according to magnitude of the monitored value after an end of receiving of each optical packet signal. | 09-24-2009 |
20090252505 | PHASE-MODULATED SIGNAL RECEIVING DEVICE - A monitor circuit detects the average light receiving current of a photoelectric conversion device for receiving a positive-phase intensity-modulated signal and outputs the detected current value to a control unit. The control unit adjusts the heater current of a phase adjustment heater in such a way as to maximize or minimize the output of the monitor circuit and controls the amount of delay of the phase reference light of a demodulator. | 10-08-2009 |
20090289664 | Signal detecting apparatus, signal receiving apparatus, and signal detecting method - A signal detecting apparatus detects a signal received based on a current received and includes a detecting unit that detects, in the current received, a peak equal to or higher than a threshold and a time counting unit that counts a given period of time from a point in time of detection of the peak by the detecting unit. The signal detecting apparatus further includes a determining unit that determines whether the detecting unit has detected the peak again within the given period of time counted by the time counting unit. An output unit of the signal detecting apparatus outputs information indicating detection of the signal received when the determining unit determines that the peak has been detected again. | 11-26-2009 |
20100103493 | Optical switch controller and movable body controller - In an optical switch controller, in order that residual vibration at movement control of a movable body such as a tilt mirror can be reduced and controlled with high accuracy, a processing unit outputs a driving signal for controlling the angle of the tilt mirror, the driving signal is D/A converted by a D/A converter and then is changed to a high-voltage signal by a high-voltage amplifier to be supplied to the tilt mirror, the electrostatic capacity of the tilt mirror changes corresponding to angle change of the tilt mirror, a mirror-angle detecting unit detects the electrostatic capacity and feeds back it as a correction value to a processing unit, and the processing unit corrects the driving signal using a correction value obtained when the angle of the tilt mirror is actually changed. | 04-29-2010 |
20100135678 | OPTICAL RECEIVING DEVICE, OPTICAL RECEIVING CIRCUIT, AND METHOD FOR RECEIVING OPTICAL SIGNALS - There is provided an optical receiving device for deriving a signal using for data identification. The optical receiving device includes a demodulator for demodulating a modulated optical signal to an demodulated optical signal, a convertor for converting the demodulated optical signal to a first and a second electric signals, a generator for generating a complement signal by summing the first electric signal of a normal in phase component and the second electric signal of a reverse in phase component, and a suppressor for suppressing, by the use of the complement signal, a variation of potential which appears in a data signal at a time of phase changing of the modulated optical signal, the data signal being a difference of the normal in phase component and the reverse in phase component. | 06-03-2010 |
20100158541 | Optical communication apparatus and optical communication method - An optical communication apparatus includes a receiver configured to receive an optical signal transmitted from an optical transmitting apparatus; a detector configured to detect a predetermined pattern signal included in the optical signal; a calculator configured to calculate, based on a waveform of the predetermined pattern signal, an amount of dispersion of the predetermined pattern signal; and a compensator configured to compensate for dispersion according to the amount of dispersion. | 06-24-2010 |
20100176877 | DIRECT-CURRENT POTENTIAL GENERATION CIRCUIT, MULTISTAGE CIRCUIT AND COMMUNICATION APPARATUS - A current source generates a direct-current potential at a terminal of a resistor by supplying a current to the resistor and a diode-connected transistor coupled to the resistor in series. | 07-15-2010 |
20110293047 | DATA RECEIVER CIRCUIT - A data receiver circuit includes: a clock/data recovery circuit to recover a clock and data from a received signal; a fixed pattern generation circuit to generate fixed pattern data; a first selection circuit to select and output one of the fixed pattern data generated by the fixed pattern generation circuit and recovered data recovered by the clock/data recovery circuit; a second selection circuit to select and output one of a reference clock and recovered clock recovered by the clock/data recovery circuit; and a switching circuit to make the first selection circuit output the fixed pattern data and to make the second selection circuit output the reference clock, when an input signal is lost or the clock/data recovery circuit is in a loss-of-lock state. | 12-01-2011 |
20120062143 | DRIVING CIRCUIT - A driving circuit for driving a diode includes at least one differential pair including a first output node and a second output node and configured to switch an output current, a current source configured to adjust the output current, a dummy load coupled to the second output node, a first termination resistor coupled between the first output node and a termination ground, and a second termination resistor coupled between the second output node and the termination ground. The output current is supplied to the diode through the first output node by at least one differential pair. | 03-15-2012 |
20130071106 | OPTICAL RECEIVER - In an optical receiver, a light receiving element receives the optical packet signals and converts the optical packet signals to electrical signals. A bias voltage supply section supplies bias voltage to the light receiving element. A monitoring section monitors an input level of each optical packet signal or each electrical signal and transmits a monitored value to the bias voltage supply section. In addition, the bias voltage supply section temporarily increases the bias voltage according to magnitude of the monitored value after an end of receiving of each optical packet signal. | 03-21-2013 |