Quantum-Dash Mode-Locked Lasers for Tunable Wavelength Conversion on a 100 GHz Frequency Grid

Abstract

All-optical wavelength converters play a key role for next-generation high-bit-rate optical networks. A high-speed, simple, and compact wavelength converter can resolve contention, reduce wavelength blocking, and enable a multitude of new wavelength routing approaches. We propose the combination of a quantum-dash mode-locked laser (QD-MLL) with a frequency-selective filter to provide (two) tunable wavelength pumps for wavelength conversion of optical channels in a dual-pump four-wave-mixing (FWM) scheme. Such a converter is simple, practical, and offers a wide conversion range, modulation format transparency, and the potential for photonic integration. We examine the performance of the proposed scheme experimentally with a QD-MLL and manually tunable optical filters. Wavelength conversion is achieved via an extremely non-linear semiconductor optical amplifier (SOA), a commercial SOA with very high FWM efficiency. We achieved near −3 dB conversion efficiency across a 9.6 nm tuning range with a signal input power of −3 dBm and a pump input power of 2 dBm. We performed bit error rate (BER) measurement on a 5.6 nm conversion range and obtained error-free transmission (BER <10−9) with less than 2 dB power penalty.