A basic introduction to ultrastable optical cavities for laser stabilization

TL;DR

This paper provides a straightforward introduction to ultrastable optical cavities, explaining their properties and use in laser stabilization, aimed at students and educators new to the field, bridging basic optics knowledge with specialized applications.

Contribution

It offers a simplified explanation of ultrastable cavity design and operation, making advanced laser stabilization techniques accessible to newcomers.

Findings

Clarifies the physics of ultrastable cavities

Provides practical guidance for setup and operation

Bridges gap between basic optics and specialized applications

Abstract

We give a simple introduction to the properties and use of ultrastable optical cavities, which are increasingly common in atomic and molecular physics laboratories for stabilizing the frequency of lasers to linewidths at the kHz level or below. Although the physics of Fabry-Perot interferometers is part of standard optics curricula, the specificities of ultrastable optical cavities, such as their high finesse, fixed length, and the need to operate under vacuum, can make their use appear relatively challenging to newcomers. Our aim in this work is to bridge the gap between generic knowledge about Fabry-Perot resonators and the specialized literature about ultrastable cavities. The intended audience includes students setting up an ultrastable cavity in a research laboratory for the first time and instructors designing advanced laboratory courses on optics and laser stabilization techniques.