All-optical single-to-dual channel non-return-to-zero to return-to-zero format converter using a periodically poled <inline-formula><math altimg="none" display="inline" overflow="scroll"><mrow><mi mathvariant="normal">Li</mi><mi mathvariant="normal">Nb</mi><msub><mi mathvariant="normal">O</mi><mn>3</mn></msub></mrow></math></inline-formula> and a reflective semiconductor optical amplifier

Abstract

Abstract. All-optical single-to-dual channel format con-verter from non-return-to-zero NRZ to return-to-zero RZis proposed and demonstrated using cascaded sum- anddifference-frequency generation SFG+DFG in a periodi-cally poled LiNbO 3 PPLN waveguide. The pump opticalclock is generated from the active mode locking in a reflec-tive semiconductor optical amplifier RSOA -based fiber ringlaser. We successfully observe 10- and 20-Gbit/s single-to-dual channel NRZ-to-RZ format conversions in theexperiment. © 2007 Society of Photo-Optical Instrumentation Engineers. DOI: 10.1117/1.2823496 Subject terms: nonlinear optics; all-optical format conversion;non-return-to-zero; return-to-zero; cascaded sum- and difference-frequency generation; periodically poled LiNbO 3 . Paper 070495LR received Jun. 14, 2007; revised manuscriptreceived Sep. 6, 2007; accepted for publication Sep. 6, 2007;published online Dec. 21, 2007. 1 Introduction An all-optical format converter is an essential element inall-optical signal processing for future high-speed telecom-munication. The basic format conversion from non-return-to-zero NRZ to return-to-zero RZ is very important andhas been successfully implemented using devices based ona nonlinear optical loop mirror