12 dB of noise reduction by a NOLM-based 2-R regenerator

We experimentally demonstrate all-optical all-passive signal regeneration by reducing the noise imposed on the signal by optical amplification by 12.03+-0.13 dB with an asymmetric nonlinear optical loop mirror (NOLM). This signal-to-noise ratio (SNR) enhancement is due to the Kerr nonlinearity which has a timescale below a few femtoseconds, thus, the SNR enhancement by the NOLM is applicable to high bit rates such as 160 Gb/s.