Phase Noise Characterization of a Mode-Locked Quantum-Dot Coherent Optical Frequency Comb Source Laser

Abstract

Modern coherent optical communication systems transmit 100 Gb/s dual-polarization quadrature phase shift keying (DP-QPSK) signals on each of the 100 channels in a dense wavelength division multiplexing (DWDM) system. Each of these channels require an individual optical carrier frequency to be generated from a discrete high-performance tunable laser. These arrays of discrete lasers are an expensive component in the transmitter of an optical communication channel. Thus, recent research has investigated an alternative laser source-optical frequency combs (OFCs). OFCs generate numerous spectral modes, referred to as comb lines, from a single photonic device. I would also like to thank Ciena and the National Research Council of Canada for providing the prototype 25 GHz coherent comb source laser.

Frequency Comb-Based WDM Transmission Systems Enabling Joint Signal Processing

“…While EO-combs can be integrated on a single chip [110], other promising comb-sources are microring resonators [52] and quantum-dash mode-locked lasers [36]. Furthermore, quantum-dot mode-locked lasers show high phase coherence [111,112]. For these comb-sources, joint processing remains to be demonstrated.…”