A novel 2R regenerator based on an asymmetric Mach-Zehnder interferometer incorporating an MMI-SOA

We propose a novel type of 2R regenerator, based on a Mach-Zehnder interferometer (MZI) with an SOA in one arm and a multi-mode-interference-coupler (MMI)-SOA in the other arm, which shows an improved regeneration characteristic compared to interferometers with 2 identical SOAs. The experimental results agree very well with the simulations. The measured static transfer function shows a digital form and a large increase in extinction ratio. An input extinction ratio of 6 dB can be improved to over 20 dB.