The present invention relates to the technical field of optical communications, and relates to an optical amplification method and an amplifier, and in particular, to a self-adaptive wave band amplification method and an amplifier. The present invention consists of a master amplifying unit and a slave amplifying unit, and can autonomously detect the service signal wave band range of an optical transmission line, and according to the detection result, the two amplifying units do not need to perform scheduling or configuration from the level of network management, and perform direct interaction and action from the bottom layer to implement self-adaptive on, off and adjustment in real time. On one hand, power consumption is reduced, and energy is saved; and on the other hand, the performance is optimized, and an optimal optical amplification index is obtained.

An optical amplifier according to the present disclosure includes a first excitation light coupler, a first optical amplification medium, a first optical switch configured to output the optical communication signal output from the first optical amplification medium to either a first branch path HGP or a second branch path, and a second optical switch configured to transmit the optical communication signal transmitted through the branch path to downstream, and the first branch HGP path includes a second optical amplification medium, a second excitation light coupler configured to synthesize the optical communication signal and the excitation light directed towards the second optical amplification medium, and a first gain equalizer, and the second branch path includes a third excitation coupler configured to synthesize the optical communication signal and the excitation light directed towards the first optical switch, and a second gain equalizer.

An optical receiver includes an optical amplifier that amplifies a received optical signal containing multiple wavelengths, a monitor circuit that monitors light intensities of the demultiplexed optical signal, a processor, and a memory having information representing a relationship between a total incident light intensity of the optical signal incident onto the optical amplifier and gains of the optical amplifier for the respective wavelengths. The processor repeats first calculation for determining the gains of the respective wavelengths from the memory, based on a drive current for driving the optical amplifier and an estimation value of the total incident light intensity of the optical signal, second calculation for calculating the incident light intensities of the respective wavelengths of the optical signal based on the gains and the monitored light intensities, and third calculation to calculate the total incident light intensity of the optical signal, until the total incident light intensity converges.

An optical transmission device includes: a first optical amplifier, a WSS (wavelength selective switch), a second optical amplifier and a controller. The first optical amplifier amplifies a received WDM (wavelength division multiplexed) optical signal. The WSS controls optical powers of respective channels multiplexed in the WDM optical signal that is amplified by the first optical amplifier. The second optical amplifier amplifies the WDM optical signal output from the WSS. The controller controls a gain of the first optical amplifier based on initial setting information. The controller corrects the gain of the first optical amplifier such that an average optical power of a plurality of channels multiplexed in the WDM optical signal that is amplified by the first optical amplifier approaches a target level after a specified period of time has elapsed from when the gain of the first optical amplifier is controlled based on the initial setting information.

A gain level control circuit in a wireless distribution system (WDS) is provided. The digital level control circuit receives a number of first digital communications signals having a number of first digital amplitudes and generates a number of second digital communications signals having a number of second digital amplitudes. When a selected second digital amplitude approaches a full-scale digital amplitude represented by a predefined number of binary bits, the gain level control circuit determines a selected first digital communications signal having a selected first digital amplitude causing the selected second digital amplitude to exceed the full-scale digital amplitude and adjusts the selected first digital amplitude to reduce the selected second digital amplitude to lower than or equal to the full-scale digital amplitude. As such, it is possible to overcome digital amplitude clipping without increasing the predefined number of binary bits, thus achieving a calculated balance between performance, complexity, and cost.

A transmission apparatus includes a demultiplexer configured to demultiplex a multiplexed signal including wavelength multiplexed signals having individual wavelength bands into a wavelength multiplexed signal for each of the wavelength bands, a detector configured to detect a power value of each of the wavelength multiplexed signals for each of the wavelength bands, first compensators configured to compensate for a tilt in the wavelength multiplexed signal based on the power value for each of the wavelength bands, second compensators configured to compensate for a power of the wavelength multiplexed signal for each of the wavelength bands so as to reduce a power difference among wavelength multiplexed signals after the tilt compensation based on the power value for each of the wavelength bands, and a multiplexer configured to multiplex each of the wavelength multiplexed signals after the power compensation and output a multiplexed signal.

A gain level control circuit in a wireless distribution system (WDS) is provided. The digital level control circuit receives a number of first digital communications signals having a number of first digital amplitudes and generates a number of second digital communications signals having a number of second digital amplitudes. When a selected second digital amplitude approaches a full-scale digital amplitude represented by a predefined number of binary bits, the gain level control circuit determines a selected first digital communications signal having a selected first digital amplitude causing the selected second digital amplitude to exceed the full-scale digital amplitude and adjusts the selected first digital amplitude to reduce the selected second digital amplitude to lower than or equal to the full-scale digital amplitude. As such, it is possible to overcome digital amplitude clipping without increasing the predefined number of binary bits, thus achieving a calculated balance between performance, complexity, and cost.

It is difficult to flatten the gain profile of an optical amplifier without increasing the power consumption, the cost, and the size of the optical amplifier; therefore, a monitoring apparatus for optical amplifier according to an exemplary aspect of the invention includes an optical filtering means for receiving a monitor light beam of the optical amplifier and transmitting a filtered monitor light beam with a set range of wavelength band; a photoelectric conversion means for converting the filtered monitor light beam into a monitoring signal; and a spectrum information generating means for generating spectrum information based on the monitoring signal, the spectrum information including information on a spectrum profile of output of the optical amplifier.

A proactive and non-obtrusive channel probing scheme is provided to accurately predict channel power, gain, and optical signal to noise ratio (OSNR) without disrupting the existing connections. In one example, using a probe signal with 5 s pulse duration in a single-hop network, rapid wavelength switching is achieved with power excursions less than or equal to 0.2 dB for different loading configurations.

A high speed satellite-based laser communications system and method for communications between a satellite-based transmitter system and a ground-based receiver over a free space optical link. The satellite-based transmitter system includes an encoder to encode data, a polarization modulator to linearly polarize the encoded data, one or at least two transmitters to transmit the laser beam, and a quarter-wave optical wave plate to circularly polarize the signal to be transmitted. The ground-based receiver includes an automatic gain control to apply AGC to the received data before the polarizations are reversed and the data is decoded. The system enables an increased data throughput and reduces or eliminates the effects of signal fading.