Patent application number | Description | Published |
20090052839 | Optical switch and control method - An optical switch includes plural ports aligned; a spectroscopic element that divides a light input to one of the ports that is an input port; plural mirrors that are aligned in a spectral direction of the light divided, and reflect the light divided; and a control unit that changes an angle of each of the mirrors so that the light reflected is output to one of the ports that is an output port, and shifts the angle in the spectral direction and a direction perpendicular to the spectral direction to attenuate the light output from the output port. | 02-26-2009 |
20090244674 | MIRROR DRIVING CIRCUIT AND OPTICAL SWITCH - A mirror driving circuit applies a voltage to drive a mirror and switches an optical path of light output from a channel of an input port to a channel of an output port. The mirror driving circuit includes an offset-voltage applying unit that applies an offset voltage to the mirror, an applied-voltage determining unit that determines an applied voltage to be applied to the mirror based on a relation between the channel of the input port and the channel of the output port forming a path of the light, and a voltage applying unit that applies to the mirror a remaining voltage obtained by subtracting the offset voltage from the applied voltage. | 10-01-2009 |
20090245727 | Optical switch and control method of optical switch, and control method of MEMS device - A control section of an optical switch calculates information relating to a polarization amount in an insulating film at each predetermined time, to update the information relating to the polarization amount in the insulating film. On the other hand, when a drive voltage is applied to a MEMS mirror, an initial value of the drive voltage corresponding to an input setting command is read out from an initial value memory, and also, the information relating to the polarization amount in the insulating film is read out from the polarization amount memory, and the initial value of the drive voltage is corrected according to the read information relating to the polarization amount in the insulating film, to thereby set a new drive voltage, and the new drive voltage is applied on electrodes of the MEMS mirror. | 10-01-2009 |
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 |
20100085630 | DEMODULATOR - A demodulator and method are provided. The demodulator for demodulating an optical signal, includes a splitter that splits a differential phase modulation signal into a first split light component and a second split light component, couples the first split light component to a first optical path and the second split light component to a second optical path, a first medium disposed on the first optical path, a second medium disposed on the second optical path and having a refractive index different from that of the first medium, and a combiner that combines the first split light component that has passed through the first medium and the second split light component that has passed through the second medium, wherein one of the first split light component and the second split light component is delayed in relation to the other. | 04-08-2010 |
20100129089 | DEMODULATOR AND RECEIVING DEVICE - A demodulator includes: a splitter that branches a differential phase shift keying optical signal into a first branched optical signal passing through a first optical path and a second branched optical signal passing through a second optical path; a multiplexer that multiplexes the first branched optical signal having passed through the first optical path and the second branched optical signal having passed through the second optical path and makes interference between the first branched optical signal and the second branched optical signal; and a double refraction medium that reduces difference between phase differences between each polarized wave between the first branched optical signal and the second branched optical signal multiplexed by the multiplexer. | 05-27-2010 |
20100134860 | MEMS DEVICE AND OPTICAL SWITCH - A micro electro mechanical system device includes a fixed electrode that includes a first electrode group; and a movable electrode that moves with respect to the fixed electrode as voltage is applied and includes a second electrode group that opposes the first electrode group. Further, electrodes of at least one among the first electrode group and the second electrode group are connected via a resistor. | 06-03-2010 |
20100284059 | DEMODULATOR - A demodulator includes a splitter, a first dielectric substance, and a combiner. The splitter splits a differential phase shift keying optical signal into a first light beam and a second light beam and outputs the first light beam to a first optical path and the second light beam to a second optical path. The first dielectric substance is disposed in the first optical path and has a refractive index higher than the average refractive index of the second optical path. The combiner combines the first light beam and the second light beam and causes the beams to interfere with each other. The difference in length between the first and second optical paths and the refractive index of the first dielectric substance are set such that the first light beam is delayed by one bit with respect to the second light beam. | 11-11-2010 |
20110217048 | Delayed interferometer and optical receiver - A delayed interferometer includes a branching unit that branches an optical signal into a first optical signal and a second optical signal; a guiding unit that guides the first optical signal in a first optical path to delay the first optical signal when a polarization direction of the first optical signal is the first direction, and guides the first optical signal in a second optical path when the polarization direction of the first optical signal is the second direction perpendicular to the first direction; a demodulating unit that causes the first optical signal guided in the first optical path or the second optical path and the second optical signal branched by the branching unit to interfere with each other, thereby demodulating the optical signal; and a polarization direction adjusting unit to adjust the polarization direction of the first optical signal in the first direction or the second direction. | 09-08-2011 |
20140269844 | APPARATUS FOR CORRECTING SIGNAL, TRANSMISSION APPARATUS, METHOD OF CORRECTING SIGNAL, AND TRANSMISSION SYSTEM - An apparatus for correcting a signal, includes a correction value calculator that determines a transmission distance of a transmission path through which a timing signal is propagated, the timing signal having a periodically changing frequency, and determines a deviation between a frequency of the timing signal and a frequency of received data, as a correction value, from the transmission distance; and a corrector that corrects the frequency of the timing signal by the correction value for synchronizing transmitted data with the timing signal. | 09-18-2014 |
20140369445 | DECISION CIRCUIT, RECEIVER DEVICE, AND PROCESSOR - A decision circuit includes: a first decision block to distinguish a first bit of bits using an amplitude of an analog signal as a discrimination point, the analog signal being an amplitude shift keyed signal; a superposition block to acquire an absolute value of a difference of the analog signal in respect to an amplitude center value of the analog signal by superposing divided analog signals; an inversion block to control inverting of the signal based on a first distinction result of the first decision block; a second decision block to distinguish a second bit of the bits based on an amplitude of an output signal from the inversion block and the discrimination point; and an output buffer to output the first distinction result and a second distinction result of the second decision block in synchronization with a clock. | 12-18-2014 |