Patent application number | Description | Published |
20090290876 | Light Receiver, Optical Communication System and Method - A receiver includes wavelength demultiplexer for demultiplexing a received WDM light into light signals at respective central frequencies thereof, delay interferometer for converting a light signal output from wavelength demultiplexer into an intensity signal, and light detector for converting an output signal from delay interferometer into an electric signal. The interval between interferential frequencies of delay interferometer is 2/(2n+1) times the interval between the central frequencies of the WDM light. Logic inverting circuit outputs the output signal from the light detector while non-inverting or inverting the logic level thereof depending on the received central frequency. | 11-26-2009 |
20100021169 | OPTICAL TRANSMISSION SYSTEM AND OPTICAL TRANSMISSION CONTROL METHOD - The present invention is intended to provide an optical transmission system which is applicable not only to a known signal but also to an unknown signal, and has a high reliability at a low cost. A branching device branches an optical transmission output of a transmitter, and transmits the branched signals through different optical transmission channels. A polarization mode dispersion monitor monitors the degree of polarization mode dispersion from the optical transmission channels at the receiving end. A switch control circuit and a switch select a signal which is less affected by a deterioration in quality due to polarization mode dispersion, and outputs the selected signal to receiver 8. In this way, the probability of a deterioration in the quality of a signal due to polarization mode dispersion can be reduced for a transmission signal. | 01-28-2010 |
20100329690 | OPTICAL COMMUNICATION SYSTEM, OPTICAL COMMUNICATION METHOD AND OPTICAL COMMUNICATION APPARATUS - Transmission-side communication apparatus | 12-30-2010 |
20110069950 | OPTICAL COMMUNICATION TRANSMISSION SYSTEM AND METHOD FOR CHECKING PERFORMANCE OF OPTICAL COMMUNICATION TRANSMISSION SYSTEM - To detect the performance degradation of an optical communication transmission system after it becoming operational, thereby preventing the reliability of the system from lowering. In an optical communication transmission system, one of optical transmitter-receivers in a redundant-structured system is an active optical transmitter-receiver, and the other optical transmitter-receiver is a standby optical transmitter-receiver. The optical transmitter-receiver includes a loopback device through which the signal light of a transmitting section of the optical transmitter-receivers is inputted to a receiving section, and an operating-system switching scheduling device for regularly switching the operating system is provided. Further, there is also provided a performance check scheduling device which operates the loopback device of the standby-system optical transmitter-receiver at a prescribed timing determined in advance to start the performance check processing by the transmitting section and the receiving section of the optical transmitter-receiver. | 03-24-2011 |
20110150465 | OPTICAL SIGNAL TRANSMISSION SYSTEMS, TRANSMITTERS, RECEIVERS, AND OPTICAL SIGNAL TRANSMISSION METHOD - An optical signal transmission system comprises a transmitter that phase-modulates two optical signals of a same frequency by asymmetrically chirping the two optical signals, combines the two optical signals that have been phase-modulated as polarization components according to polarization multiplexing, and transmits an optical signal that has been combined and obtained; and a receiver that receives said optical signal from said transmitter, compresses pulses of at least one of the polarization components of the optical signal, and splits the optical signal into two polarization components. | 06-23-2011 |
20150078744 | MULTIPLEXED OPTICAL TRANSMISSION LINE, OPTICAL TRANSMISSION SYSTEM, AND OPTICAL TRANSMISSION METHOD - It is difficult in an optical transmission system using a multicore optical fiber to provide high-capacity transmission in which good signal quality is obtained, therefore, a multiplexed optical transmission line according to an exemplary aspect of the present invention includes at least one first optical transmission line propagating first signal light in a first direction; and at least one second optical transmission line propagating second signal light in a second direction opposite to the first direction, wherein the second optical transmission line is disposed in at least one of positions adjacent to the first optical transmission line wherever the first optical transmission line may be disposed. | 03-19-2015 |