In-band Amplified Spontaneous Emission Noise Filtering with a Dispersion-Imbalanced Nonlinear Loop Mirror

We report removal of in-band amplified spontaneous emission (ASE) noise in a 10 Gb/s noise-loaded RZ signal using a dispersion-imbalanced loop mirror. The resulting receiver sensitivity is improved from -37.0 dBm to -37.7 dBm. The loop mirror bias dependence on sensitivity is also investigated, and the optimal bias point is found to be where the loop transmissivity decreases with increasing input power.