8results about "Multiple station single light source" patented technology

The application discloses a communication method, device, system and train, relates to the field of optical fiber communication, and is applied to a processor in any compartment of a train, wherein the processor is connected with an optical fiber ring network, the processor and train communication equipment in the compartment perform communication data interaction, and then the processor and the optical fiber ring network perform communication data interaction in the form of optical signals, so that the train communication equipment in different compartments can communicate with each other. The communication data is not easy to be lost and is not easy to be affected by electromagnetic interference through the mode of data transmission by optical fibers instead of cables, so that the communication quality of the train communication equipment is improved. Moreover, the communication data of multiple train communication equipments is converted into optical signals and transmitted in the form of a bundle of light, so that multiple communication networks are not needed, and only one optical fiber ring network can realize data transmission of multiple train communication equipments at the same time, so that the complexity of the wiring environment in the train is reduced, and the total weight of the train is reduced.

The present application provides an optical transmission method and device for reducing or eliminating phase noise, and relates to the field of communication. A first optical transmission device includes a first circulator and a first receiving module. The first receiving module is coupled to the first circulator. The first circulator is configured to receive a second unmodulated optical signal from a second optical transmission device. The first receiving module is configured to receive a second modulated optical signal from the second optical transmission device and receive the second unmodulated optical signal from the first circulator. The second modulated optical signal is obtained by modulating the first unmodulated optical signal, the second unmodulated optical signal is used to coherence detect the second modulated optical signal, the first unmodulated optical signal and the second unmodulated optical signal are obtained by separating a third unmodulated optical signal, and the third unmodulated optical signal is an optical signal provided from the first optical transmission device to the second optical transmission device.

An optical module includes a processing component and a plug component. The plug component includes a plurality of filters. The plurality of filters are connected to a plurality of secondary ports. The processing component includes a plurality of primary ports. The optical module is in a first connection status or a second connection status. When the optical module is respectively in the first connection status or the second connection status, a wavelength of a second service optical signal or a wavelength of a second local oscillator optical signal that are sent by the plurality of filters varies. When the optical module is in a same connection status, wavelengths of the second service optical signal and the second local oscillator optical signal that are sent by the plurality of filters are identical.

A modulator unit for modulating the polarization of an optical signal includes a light source, a polarization-dependent phase modulator, and a reflector. The light source outputs an optical signal and emits it as the input signal directed at the phase modulator. The optical signal contains a first and a second polarization components having a first and a second polarization directions, respectively. The phase modulator modulates a first phase of the first polarization component in the first polarization direction and passes on the modulated input signal to the reflector. The reflector retroreflects the received optical signal towards the phase modulator and changes its polarization by 90°. The phase modulator modulates a second phase of the second polarization component of the retroreflected optical signal in the first polarization direction. The modulator unit outputs the modulated optical signal as the polarization-modulated output signal.

The invention relates to a bidirectional communication device between a first terminal (4) and at least one second terminal (6), comprising: - a single optical fiber (2) between the first terminal (4) and at least one second terminal (6); - the first terminal (4) comprising a radiation source (8) at at least one first wavelength (λ1), a photodetector (10), and means (12) for directing a signal from the second terminal (6) via the optical fiber (2) to the photodetector (10) and for directing a signal from the radiation source (8) to the optical fiber (2); - the second terminal (6) comprising at least one modulator (24), a photodetector (22), and power supply means (9). Figure 1

A communication method, which relates to the field of optical fiber communications, is applied to a processor in any carriage of a train. The processor is connected to an optical fiber ring network, and the processor performs communication data interaction with a train communication device in a carriage, and then performs communication data interaction in an optical signal form with the optical fiber ring network, so as to implement communication between the train communication devices in different carriages.

In an embodiment, a coherent optical communication system (100) is provided. The coherent optical communication system comprises a first optical source (102) configured to generate a first optical supply signal; a first side communication system (104) comprising a first side transmitter (106); a first side optical supply connection (108) configured to supply the first optical supply signal to the first side transmitter; a second side communication system (110) comprising a second side receiver (112); a second side optical supply connection (114) configured to supply the first optical supply signal to the second side receiver; and an optical communication connection (116) between the first side transmitter and the second side receiver. The first side transmitter is configured to: modulate the first optical supply signal with first information to generate a first modulated signal; and transmit the first modulated signal to the second side receiver via the optical communication connection. The second side receiver is configured to use the first optical supply signal to perform coherent detection on the first modulated signal.

Injection-locked transmitter for an optical communications network, comprising: a master seed laser source input that is limited to a single longitudinal mode; an input data stream; and a laser-injected modulator comprising at least one slave laser with a resonator frequency locked to a frequency of the single longitudinal mode of the master-seed laser source, wherein the laser-injected modulator is configured to receive the master-seed laser source input and the input data stream and to output a laser-modulated data stream, characterized by the fact that the transmitter further comprises: a first optical circulator in communication with the laser-injected modulator and the master-seed laser source input; a second optical circulator in one-way communication with the first optical circulator and in two-way communication with the at least one slave laser; and an external modulation element located between the first optical circulator and the second optical circulator, wherein the external modulation element is configured to receive the input data stream and an output from the second optical circulator, where the first optical circulator is in one-way communication with an output of the external modulation element.