Tunable optical frequency comb with hundred-GHz spacings generated on a silicon waveguide

We demonstrate the generation of optical frequency combs with tunable spacing at the hundred-GHz range in the 1550nm window. The widely spaced combs are realized through silicon-based cross-phase modulation. The optical pump is prepared by multiplication of a 10-GHz train of 1.7-ps pedestal-free pulses. Energy-efficient temporal Talbot processing is used to multiply the repetition rate by a factor of up to 20. In our approach, the multiplication factor can be flexibly controlled by tuning the temporal dispersion inside an optical processor. Optical frequency combs with spacings ranging from 140 to 200 GHz have been successfully generated with a maximum carrier-to-noise suppression ratio of similar to 45 dB. (C) 2022 Optica Publishing Group

Automated summary

Researchers have successfully demonstrated the generation of optical frequency combs with tunable spacing in the 1550nm window. They achieved widely spaced combs through silicon-based cross-phase modulation and multiplied the repetition rate by up to a factor of 20 using energy-efficient temporal Talbot processing.