Radiation pressure in finite Fabry-P\'erot cavities

TL;DR

This paper investigates how finite size and misalignment affect a Fabry-Pérot cavity's ability to detect mirror motion through output light intensity, with implications for practical optomechanical devices.

Contribution

It provides a detailed analysis of light confinement and motion detection in realistic, imperfect Fabry-Pérot cavities, extending understanding beyond idealized models.

Findings

Motion of the movable mirror can be traced via output intensity changes despite imperfections.

Finite size and misalignment influence intracavity and output field behavior.

The results are relevant for transitioning optomechanics from research to commercial applications.

Abstract

We study the effect of finite size and misalignment on a fundamental optomechanical setup: a Fabry-P\'erot cavity with one fixed and one moveable mirror. We describe in detail light confinement under these real world imperfections and compare the behaviour of the intracavity and output fields to the well-known ideal case. In particular, we show that it is possible to trace the motion of the movable mirror itself by measuring intensity changes in the output field even in the presence of fabrication shortcomings and thermal noise. Our result might be relevant to the transition from high precision research experiments to everyday commercial applications of optomechanics; such as high-precission stepmotor or actuator positioning.