Heterodyne Gain and Noise Measurement of a 1.5 mu m Resonant Semiconductor Laser Amplifier.
01 January 1986
The noise and gain characteristics of 1.5 mu m resonant semiconductor laser amplifier have been measured. A heterodyne detection scheme was used to measure the gain and noise properties relevant to coherent communication applications. Measurements were made with the amplifier operating in unsaturated, saturated, and injection locked regimes. Unsaturated internal gain as high as 29 dB was measured with the amplifier operating close to threshold. Measured signal-to-noise ratios agree well with calculated results and are 9 dB below the input quantum shot noise limit. A degradation in the amplifier performance is observed when operated above or at threshold. Gain saturation, for high input powers, also degrades the noise characteristics of the amplifier.