Generating optical frequency combs via nanoscale photonic structures

In this paper, a novel method to generate optical frequency combs (OFCs) using nanoscale structures is explored. The growing demand for on-chip photonic processing dictates the need for multi-wavelength light sources, such as OFCs, that can be densely integrated with low processing power. Photonic crystal structues provide a viable method to generate all-optical modulation with sub-femto joule switching power and high density integration potential. This method of all-optical modulation is utilised here to generate an OFC from photonic crystal nanocavities and waveguides. Very-flat-topped optical frequency combs with a small intensity variation can be generated based on theoretical predictions via detailed analysis of coupled mode theory for photonic crystal nanocavities and waveguides.