Method for locking Raman gains of target and Raman OFA (optical fiber amplifier)

Abstract

The invention discloses a method for locking Raman gains of a target and a Raman OFA (optical fiber amplifier). The OFA comprises a coupler and a control unit, wherein the control unit comprises a gain locking module; and a detection circuit formed by a filter and an optical power detector is connected between the output end of the coupler and the input end of the control unit. In the method, the control unit is utilized to adjust the power of a pump laser, thus the power of detected OOB (out of band) ASE (amplified spontaneous emission) optical signals is consistent with that of the targeted OOB ASE optical signals, and the amplification gains of the target is locked. The optical path structure of the OFA is simple, the Raman gains can be configured flexibly in accordance with the circuit conditions, and the gains of the Raman OFA can be automatically controlled and locked.

Description

technical field [0001] The present invention belongs to the field of communication, and in particular relates to a Raman optical fiber amplifier and a method for locking the target gain. Background technique [0002] At present, distributed Raman fiber amplifiers have been widely used in communication systems. Since the gain medium of distributed Raman amplifiers is the transmission fiber itself, the input power entering the Raman pump module cannot be monitored in real time. Only when the pump is turned off In order to detect the signal power entering the Raman pump module, if the pump laser of the Raman pump module is on, then the signal power entering the Raman pump module is the amplified power, that is to say, the pump The pump module cannot detect both the input power when the pump is turned off and the signal power when the pump is turned on at the same time, so the gain control of the distributed Raman fiber amplifier cannot be controlled by comparing the input and o...

AI Technical Summary

Problems solved by technology

There are two points that need to be improved in this method on the value of ASE: 1. The value is selected near the working wavelength, the bandwidth is not wide enough, the obtained ASE power value is relatively very small, and the dark current of the PIN will bring a relatively large impact on the gain accuracy. Influence; 2. The ASE value is selected near the working wavelength. Although the bandpass filter is a non-ITU-T standard channel, the SSE of the light source itself will also have a relatively large impact on the ASE power, especially for 40Gbit / s and 100Gbit / s signal, the signal bandwidth is relatively wide, the SSE power of many substrates will crosstalk to the value range of ASE, and another unavoidable phenomenon is that the ASE power generated by EDFA in the system cascade is unavoidable of

The above two points will restrict the feasibility of the technology

In addition, this patent only performs gain locking for a certain fixed gain, and there is no realization method for variable gain

[0006] Patent CN101552428A describes a technology and device for realizing signal power detection and ASE compensation based on the method of detecting ASE power outside the operating bandwidth of the Raman amplifier and ASE and signal power within the operating bandwidth. This patent only uses the out-of-band ASE In-band ASE power detection is carried out to realize signal power monitoring, and ASE power is not used for gain locking and adjustment. In addition, this solution does not involve the influence of EDFA's own out-of-band ASE on the entire signal power detection in the system. Because the main purpose of this patent is to solve the pump-off problem when the fiber is broken or there is no signal light, the out-of-band ASE of the EDFA in the system has little effect on it, because when the fiber is broken or there is no signal light input, the EDFA There is no ASE power output per se

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