Photothermal effect in macroscopic optomechanical systems with an intracavity nonlinear optical crystal

TL;DR

This paper investigates how the photothermal effect influences intracavity optomechanical systems with nonlinear crystals, proposing a new measurement method to accurately estimate photothermal parameters and their impact on optomechanical coupling.

Contribution

It introduces a novel approach to predict photothermal effects by measuring susceptibility, enabling precise estimation of parameters even for minor effects.

Findings

Successfully estimated photothermal parameters with high precision.

Demonstrated the method's ability to detect subtle photothermal influences.

Provided insights into the modification of optomechanical coupling due to photothermal effects.

Abstract

Intracavity squeezing is a promising technique that may improve the sensitivity of gravitational wave detectors and cool optomechanical oscillators to the ground state. However, the photothermal effect may modify the occurrence of optomechanical coupling due to the presence of a nonlinear optical crystal in an optical cavity. We propose a novel method to predict the influence of the photothermal effect by measuring the susceptibility of the optomechanical oscillator and identifying the net optical spring constant and photothermal absorption rate. Using this method, we succeeded in precisely estimating parameters related to even minor photothermal effects, which could not be measured using a previously developed method.