Frequency comb generation via synchronous pumped $\chi^{(3)}$ resonator on thin-film lithium niobate

TL;DR

This paper demonstrates broadband optical frequency comb generation in a thin-film lithium niobate resonator using synchronous pulsed pumping, overcoming previous limitations of microresonator tuning and Raman scattering effects.

Contribution

It introduces a method for broadband comb generation in a $$ resonator with tunable femtosecond pulses and on-chip modulators, advancing chip-scale frequency comb technology.

Findings

Broadband comb generation achieved in thin-film lithium niobate resonator.

Pulsed pumping overcomes limitations of crystalline resonators.

Enhanced tunability and comb bandwidth demonstrated.

Abstract

Resonator-based optical frequency comb generation is an enabling technology for a myriad of applications ranging from communications to precision spectroscopy. These frequency combs can be generated in nonlinear resonators driven using either continuous-wave (CW) light, which requires alignment of the pump frequency with the cavity resonance, or pulsed light, which also mandates that the pulse repetition rate and cavity free spectral range (FSR) are carefully matched. Advancements in nanophotonics have ignited interest in chip-scale optical frequency combs. However, realizing pulse-driven on-chip Kerr combs remains challenging, as microresonator cavities have limited tuning range in their FSR and resonance frequency. Here, we take steps to overcome this limitation and demonstrate broadband frequency comb generation using a $\chi^{(3)}$ resonator synchronously pumped by a tunable femtosecond pulse generator with on-chip amplitude and phase modulators. Notably, employing pulsed pumping overcomes limitations in Kerr comb generation typically seen in crystalline resonators from stimulated Raman scattering.