Erbium doped fiber amplifier real time detection system

Abstract

The invention provides an erbium doped fiber amplifier real time detection system. A main optical path of an erbium doped fiber amplifier is connected with a bandpass filtering module. A data analysis module, a filtering module and a narrowband power detection module are set. After signals of an input end or an output end pass through the bandpass filtering module and the filtering module, short wavelengths and long wavelengths enter the data analysis module through the narrowband power detection module. The wideband characteristics of spontaneous emission noise of the fiber amplifier are utilized; real-time online detection of system indexes (input / output OSNR, signal gain, noise index and the like) of nodes of an optical transmission system including the fiber amplifier can be achieved; the structure is simple and the response is in time; and significance is provided for system performance monitoring, network management, system installation and maintenance, and the like.

Description

technical field [0001] The invention relates to the technical field of real-time optical signal-to-noise ratio monitoring in optical communication, in particular to a real-time detection system for an erbium-doped optical fiber amplifier. Background technique [0002] Optical fiber amplifiers are indispensable and important components in long-distance optical fiber communication systems, especially Erbium-doped optical fiber amplifiers (EDFA), because of their high gain, large bandwidth, high saturated output power, and low noise figure, they have become the most commercially available optical fibers. amplifier. The disadvantage is that the erbium-doped fiber amplifier amplifies the spontaneous emission noise while amplifying the optical signal, and the accumulated spontaneous emission noise causes the degradation of the optical signal-to-noise ratio (OSNR) of the system, thus limiting the optical fiber communication system without electrical relay. Transmission distance. ...

AI Technical Summary

Problems solved by technology

The disadvantage is that the erbium-doped fiber amplifier amplifies the spontaneous emission noise while amplifying the optical signal, and the accumulated spontaneous emission noise causes the degradation of the optical signal-to-noise ratio (OSNR) of the system, thus limiting the optical fiber communication system without electrical relay. Transmission distance

[0003] The spontaneous emission noise generated by the erbium-doped fiber amplifier itself is a relatively smooth noise spectrum line. The current commonly used test is to use this characteristic, using P i The noise level between adjacent peaks, that is, the distance from the channel center wavelength λ i Noise power N at each Δλ on the left and right i (λ i -Δλ) and N i (λ i +Δλ) to the noise power under the peak N i (λ i ) for interpolation fitting (such as figure 1 As shown), to test the noise figure of EDFA, but the current test is to rely on the spectrum analyzer to test the light source and EDFA separately and get the noise figure of EDFA after complicated calculation

Another method is to use the non-polarization characteristic of spontaneous emission noise to detect the signal light with polarization characteristics and the noise without polarization characteristics separately, which will be difficult for DWDM (Dense Lightwave Multiplexing) with multiple channels to use EDFA Be applicable

These two methods are more complicated in actual application, and need to be realized with the help of a spectrum analyzer, etc., and it is difficult to realize online real-time monitoring

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