Abstract:
A device having a partially reflective cover, in particular for use as a decorative mirror element, is described. The device comprises a light source and a cover, which is arranged in front of the light source, the cover comprising a reflective polarizer and a circular polarizer, which is arranged behind the reflective polarizer.
Abstract:
A device having a partially reflective cover, in particular for use as a decorative mirror element, is described. The device comprises a light source and a cover, which is arranged in front of the light source, the cover comprising a reflective polarizer and a circular polarizer, which is arranged behind the reflective polarizer.
Abstract:
A phase shift unit provides a prescribed phase difference (π/2, for example) between a pair of optical signals transmitted via a pair of arms constituting a data modulation unit. A low-frequency signal f0 is superimposed on one of the optical signals. A signal of which phase is shifted by π/2 from the low-frequency signal f0 is superimposed on the other optical signal. A pair of the optical signals is coupled, and a part of which is converted into an electrical signal by a photodiode. 2f0 component contained in the electrical signal is extracted. Bias voltage provided to the phase shift unit is controlled by feedback control so that the 2f0 component becomes the minimum.
Abstract:
An interferometer for demodulating a differential M-phase shift keying signal includes a PLC type interferometer main body, a heating portion that heats the PLC type interferometer main body, and an intermediate member having a higher stiffness than that of the PLC type interferometer main body, for bonding the PLC type interferometer main body and the heating portion with each other while being sandwiched therebetween. A linear expansion coefficient difference between the PLC type interferometer main body and the intermediate member is equal to or smaller than 4.5×10−6/° C., and a thermal conductivity difference between the PLC type interferometer main body and the intermediate member is equal to or larger than 10 W/mK. A phase of an optical signal flowing through the interferometer is adjusted by using the heating portion and a second heating portion.
Abstract:
A data modulator unit generates a DQPSK optical signal in accordance with a data signal. A phase shift unit provides a phase difference of π/2 between a pair of arms. A photodetector converts an output signal of the data modulator unit into an electrical signal. A filter is a low-pass filter with a cut-off frequency lower than a symbol frequency, and filters an output signal of the photodetector. A monitor unit detects power of an output signal of the filter. A phase difference control unit adjusts the amount of phase shift in the phase shift unit so as to minimize power of an output signal of the filter.
Abstract:
In the optical reception apparatus, a DQPSK polarization multiplexed signal light (S) input thereto is split into horizontally/vertically polarized signal lights (SH, SV) by a polarization beam splitter (3), and the signal lights (SH, SV) each is branched into two by each of optical couplers (4H, 4V). Then, one branched lights (SH1, SV1) by each of the optical couplers (4H, 4V) are supplied to a delay interferometer (5I) on the I branch via optical circulators (10I1, 10I2) to be propagated in bidirectional, and the other branched lights (SHQ, SVQ) by each of the optical couplers (4H, 4V) are supplied to a delay interferometer (5Q) on the Q branch side via optical circulators (10Q1, 10Q2) to be propagated in bidirectional, so that a set of delay interferometers (5I, 5Q) is commonly used for horizontally polarized waves and vertically polarized waves.
Abstract:
A calculation processing unit controls temperature of a Peltier device based on a slope of a waveform obtained by subtracting a waveform of a B-arm monitoring signal from a waveform of an A-arm monitoring signal and a value obtained by subtracting a value B of the B-arm monitoring signal from a value A of the A-arm monitoring signal. Similarly, the calculation processing unit controls a phase of the A-arm and a phase of the B-arm. An A-arm side micro-controller controls temperature of an A-arm side heater 22 based on the value of the A-arm monitoring signal, and controls the phase of the A-arm. A B-arm side micro-controller controls temperature of a B-arm side heater based on the value B of the B-arm monitoring signal, and controls the phase of the B-arm.
Abstract:
Influence of polarization mode dispersion, occurring in an optical fiber is mitigated by means of polarization scrambling, differential group delay which a received optical signal has is optically suppressed; the optical signal in which differential group delay is thus suppressed is converted into an electric signal; and error correcting processing is carried out on the electric signal obtained, a jitter amplitude in the received optical signal is suppressed, influence of which to a jitter tolerance increases due to increase in speed of the polarization scrambling.
Abstract:
An apparatus and a method for a I-Q quadrature modulation transmitter monitor a phase bias between an I branch and a Q branch of the I-Q quadrature modulation transmitter. The I-Q quadrature modulation transmitter includes the I-branch, the Q-branch equipped with a phase bias, and a tap. The apparatus is installed between the tap and the phase bias, and monitors the phase between the I branch and the Q branch which phase is introduced by the phase bias. The apparatus includes the following components: a module squarer, receiving signal from the tap and outputting a module square of the received signal; a multiplier, to multiplying data of the I-branch, data of the Q-branch and the module square to output a multiplied signal; and an averager, averaging the multiplied signal output by the multiplier. The phase between the I branch and the Q branch may be corrected according to monitoring results.
Abstract:
A media object is scheduled for transmission between a server and a client. The media object is partitioned into segments of blocks, wherein each block is a unit of media for which a client will wait to receive an entire block before playing out the block, and wherein each segment includes an integer number of blocks. One or more channels on which to serve each segment are determined, and a rate at which to serve each segment is determined. Additionally, a schedule pair for each channel is determined. The schedule pair includes a time at which the client may start receiving on the channel and a time at which the client may stop receiving on the channel.