Photothermal effects in ultra-precisely stabilized tunable microcavities

作者：Brachmann Johannes F S; Kaupp Hanno; Haensch Theodor W; Hunger David^*

来源：Optics Express, 2016, 24(18): 21205-21215.

DOI：10.1364/OE.24.021205

We study the mechanical stability of a tunable high-finesse microcavity under ambient conditions and investigate light-induced effects that can both suppress and excite mechanical fluctuations. As an enabling step, we demonstrate the ultra-precise electronic stabilization of a microcavity. We then show that photothermal mirror expansion can provide high-bandwidth feedback and improve cavity stability by almost two orders of magnitude. At high intracavity power, we observe self-oscillations of mechanical resonances of the cavity. We explain the observations by a dynamic photothermal instability, leading to parametric driving of mechanical motion. For an optimized combination of electronic and photothermal stabilization, we achieve a feedback bandwidth of 500 kHz and a noise level of 1.1 x 10(-13) m rms.

• 出版日期2016-9-5