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Generation of tunable, high repetition rate optical frequency combs using on-chip silicon modulators
preprintposted on 2023-11-30, 05:40 authored by Kp Nagarjun, Vadivukarassi Jeyaselvan, Shankar Kumar Selvaraja, V R Supradeepa
We experimentally demonstrate tunable, highly-stable frequency combs with high repetition-rates using a single, charge injection based silicon PN modulator. In this work, we demonstrate combs in the C-band with over 8 lines in a 20-dB bandwidth. We demonstrate continuous tuning of the center frequency in the C-band and tuning of the repetition-rate from 7.5GHz to 12.5GHz. We also demonstrate through simulations the potential for bandwidth scaling using an optimized silicon PIN modulator. We find that, the time varying free carrier absorption due to carrier injection, an undesirable effect in data modulators, assists here in enhancing flatness in the generated combs.