In-band amplified spontaneous emission noise filtering with a dispersion-imbalanced nonlinear loop mirror

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