Gazi Mohammad SHARIF^1*, Quang NGUYEN-THE¹, Motoharu MATSUURA², and Naoto KISHI¹

¹Department of Communication Engineering and Informatics, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
²Center for Frontier Science and Engineering, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan

(Received December 17, 2012; Accepted March 21, 2013)

We demonstrate polarization-insensitive non-return-to-zero (NRZ)-to-pulsewidth tunable return-to-zero (RZ) conversion based on a Raman amplifier (RA)-based pulse compressor and a fiber-based NRZ-to-RZ converter, which consists of a polarization diversity loop. We measure the bit-error rate (BER) characteristics of the input NRZ signal and the converted RZ signals. The power penalty of less than 0.2 dB between the converted RZ signals with different power ratios proved the polarization insensitivity. Moreover, by changing the Raman pump power of the RA-based pulse compressor, the pulsewidths of the converted RZ signals were flexibly tuned from 10 to 2 ps, which proved NRZ-to-RZ conversion with pulsewidth tunability. In all cases, clear eye diagrams were obtained.

Key words: NRZ-to-RZ conversion, pulsewidth-tunable operation, Raman amplifier, four-wave mixing (FWM)

^*E-mail address: gazi.sharif@uec.ac.jp