hide
Free keywords:
Physics, Optics, physics.optics,General Relativity and Quantum Cosmology, gr-qc
Abstract:
We report on the observation of photo-thermal feed-back in a stable
dual-carrier optical spring. The optical spring is realized in a 7 cm
Fabry-Perot cavity comprised of a suspended 0.4 g small end mirror and a heavy
input coupler, illuminated by two optical fields. The frequency, damping and
stability of the optical spring resonance can be tuned by adjusting the power
and detuning of the two optical fields, allowing for a precise measurement of
the absorption-induced photo-thermal feedback. The magnitude and frequency
dependence of the observed photo-thermal effect are consistent with predicted
corrections due to transverse thermal diffusion and coating structure. While
the observed photo-thermal feed-back tends to destabilize the optical spring,
we also propose a small coating modification that would change the sign of the
effect, making a single-carrier stable optical spring possible.
