Conversion efficiency of soliton Kerr combs

We investigate the conversion efficiency (CE) of soliton modelocked Kerr frequency combs. Our analysis reveals three distinct scaling regimes of CE with the cavity free spectral range (FSR), which depends on the relative contributions of the coupling and propagation loss to the total cavity loss. Our measurements, for the case of critical coupling, verify our theoretical prediction over a range of FSRs and pump powers. Our numerical simulations also indicate that mode crossings have an adverse effect on the achievable CE. Our results indicate that microresonator combs operating with spacings in the electronically detectable regime are highly inefficient, which could have implications for integrated Kerr comb devices. (C) 2021 Optical Society of America

Automated summary

Our study investigates the conversion efficiency of soliton modelocked Kerr frequency combs, revealing three distinct scaling regimes with the cavity free spectral range. We verify our theoretical predictions through measurements for critically coupled cases and find that mode crossings have a negative impact on achievable CE. Our results suggest that microresonator combs with spacings in the electronically detectable regime are highly inefficient, which could impact integrated Kerr comb devices.