Optical-Amplifier Noise-Figure Measurement by Q-Factor Analysis

In the semi-classical picture of linear optical ampliers, the amplier output is considered as a mixture of an amplied signal and amplied spontaneous emission (ASE). The amplied signal is a coherent eld with Poisson statistics, and the ASE can be well described as a thermal eld. This simple picture, however, can be fully justied quantum mechanically. It has been shown that the signal-to-noise ratio, and hence the noise gure of a linear optical amplier, can be determined by measuring the Q-factor of the amplied continuous wave (CW) signal modulated with a low extinction-ratio external modulator. KCI Citation Count: 1