Szabados, JanJanSzabadosBrasch, VictorVictorBraschHerr, Simon J.Simon J.HerrObrzud, EwelinaEwelinaObrzudJia, YuechenYuechenJiaLecomte, SteveSteveLecomteBuse, KarstenKarstenBuseBreunig, IngoIngoBreunigHerr, TobiasTobiasHerr2022-03-142022-03-142019https://publica.fraunhofer.de/handle/publica/40404910.1117/12.2510304Optical frequency combs are a key technology for optical precision measurements. So far, most frequency combs operate in the near-infrared regime (NIR). Many applications, however, require combs in the ultraviolet (UV), visible (VIS) or mid-infrared (MIR) spectral ranges. This can be achieved by making use of nonlinear-optical processes. In this contribution, we demonstrate the efficient conversion of frequency combs with a repetition rate of 21 GHz to UV, VIS and MIR wavelengths in a synchronously driven high-Q microresonator with second-order optical nonlinearity. This opens up a new path for applications including, but not limited to, molecular sensing and quantum optics.enoptical frequency combnonlinear optichigh-Q microresonatorsecond harmonic generationfrequency conversionlithium niobateoptical parametric oscillatornear infraredultraviolet radiation621conference paper