Abstract: An optical relay system is provided, which includes a first optical signal distribution device (101), a phase detection device (103), an amplitude regeneration device (102), and a phase regeneration and load device (104). An optical relay method is further provided, which includes the following steps. A received input signal is divided into two paths; phase information of one path of the input signal is extracted, and is converted to an amplitude modulated signal; an amplitude of the other path of the input signal is restored, so as to generate an amplitude regenerated signal; a phase is loaded on the amplitude regenerated signal by using the amplitude modulated signal, so as to generate a phase regenerated signal. The system and method eliminate a phase noise of the signal in a transmission process, improve a transmission performance of the signal, and realize a simple implementation method.

Abstract: The method includes: splitting an optical carrier into two or more sets of optical sub-carriers at a receiving end; respectively performing optical PDM on each set of the optical sub-carriers to obtain two sets of to-be-demodulated optical signals; and extracting a part of signals from each set of the to-be-demodulated signals to calculate features characterizing polarization states, controlling feedback signals according to the features, and correspondingly adjusting a polarization state of each set of the optical sub-carriers. With the device combining optical division into two or more sets of sub-carriers with optical PDM, an optical carrier signal can be split in an optical modulation format into four or more sets of signals for processing, and delay interference can be performed directly on an optical wave by using Differential Quadrature Phase Shifted Keying (DQPSK) demodulators to obtain by detection output signals.

Abstract: An optical relay system is provided, which includes a first optical signal distribution device (101), a phase detection device (103), an amplitude regeneration device (102), and a phase regeneration and load device (104). An optical relay method is further provided, which includes the following steps. A received input signal is divided into two paths; phase information of one path of the input signal is extracted, and is converted to an amplitude modulated signal; an amplitude of the other path of the input signal is restored, so as to generate an amplitude regenerated signal; a phase is loaded on the amplitude regenerated signal by using the amplitude modulated signal, so as to generate a phase regenerated signal. The system and method eliminate a phase noise of the signal in a transmission process, improve a transmission performance of the signal, and realize a simple implementation method.

Abstract: A method, device, and system for polarization division multiplexing (PDM) and polarization division demultiplexing are provided in the field of communication and transmission. The device for polarization division demultiplexing includes a polarization controller (PC), a polarization beam splitter (PBS), a detection control module, an optoelectronic receiver 1, and an optoelectronic receiver 2. The PC is adapted to receive a PDM optical signal carrying an identification signal and perform polarization control on the PDM optical signal. The PBS is adapted to perform polarization division on the PDM optical signal carrying the identification signal after the polarization control. The detection control module is adapted to perform identification signal detection on the optical signal after the polarization division to obtain a power of the identification signal, and output a polarization control signal to control the PC according to a power change of the identification signal.

Abstract: The present invention discloses an optical communication system, a sub-rate multiplexing/de-multiplexing apparatus and the method thereof such that the optical communication system could meet the demand of Metropolitan Area Network (MAN) communications using the existing optical fiber network. This optical communication system includes an optical transmitting module and an optical receiving module connected by optical fibers, wherein the optical transmitting module is used for converting the inputted electrical signals into optical signals and transferring the optical signals to the optical receiving module via optical fibers, and the optical receiving module is used for converting the received optical signals into electrical signals and outputting the electrical signals. In the optical signals transferred by optical fibers, the data transmission rate of at least one wavelength is about 5 Gb/s.

Abstract: Disclosed is a method for transmitting Ethernet service signals in a Wavelength Division Multiplexing (WDM) network, including: a Center receiving Ethernet service signals and transmitting the signals to a transmission channel; a receiving station receives the Ethernet service signals, performs a space-division cross operation upon the received signals, duplicates the signals into two copies, where one is locally downloaded while the other is returned to the transmission channel. Three devices for processing the Ethernet service signals in the WDM network are provided. With the present invention, the broadcast of the Ethernet service signals with large granularity is implemented, therefore decreasing the delay for broadcast the real-time services; besides, it is not necessary anymore to construct a overlapped network with three layers of devices, i.e. a WDM system, a Synchronous Digital Hierarchy (SDH) system and a data device, so the network structure is simplified and management is convenient.

Abstract: The invention discloses an on-line dispersion compensation device for a wavelength division optical transmission system. The device is consisted of two optical path selectors and at least one chirped grating fiber unit. The chirped grating fiber unit is consisted of two chirped grating fibers with same wavelength band and connected oppositely. In addition, the chirped grating fiber unit is serially connected between the appropriate ports of the two optical path selectors. The invention applies a structure that combines a chirped grating fiber unit with two optical path selectors. The structure is suitable to on-line dispersion compensation in a DWDM system and has low insertion loss. When only a few wavelengths need to be compensated, the structure makes dispersion compensation with low cost, low insertion loss and compensating a large dispersion value. For single channel or broadband compensation, the invention provides dispersion compensation without through OADM or MUX/DEMUX filtering.

Abstract: The present invention discloses an optical communication system, a sub-rate multiplexing/de-multiplexing apparatus and the method thereof such that the optical communication system could meet the demand of Metropolitan Area Network (MAN) communications using the existing optical fibre network. This optical communication system includes an optical transmitting module and an optical receiving module connected by optical fibres, wherein the optical transmitting module is used for converting the inputted electrical signals into optical signals and transferring the optical signals to the optical receiving module via optical fibres, and the optical receiving module is used for converting the received optical signals into electrical signals and outputting the electrical signals. In the optical signals transferred by optical fibres, the data transmission rate of at least one wavelength is about 5 Gb/s.

Abstract: The invention discloses an on-line dispersion compensation device for a wavelength division optical transmission system. The device is consisted of two optical path selectors and at least one chirped grating fiber unit. The chirped grating fiber unit is consisted of two chirped grating fibers with same wavelength band and connected oppositely. In addition, the chirped grating fiber unit is serially connected between the appropriate ports of the two optical path selectors. The invention applies a structure that combines a chirped grating fiber unit with two optical path selectors. The structure is suitable to on-line dispersion compensation in a DWDM system and has low insertion loss. When only a few wavelengths need to be compensated, the structure makes dispersion compensation with low cost, low insertion loss and compensating a large dispersion value. For single channel or broadband compensation, the invention provides dispersion compensation without through OADM or MUX/DEMUX filtering.