# Microresonator-stabilized extended cavity diode laser for supercavity frequency stabilization

## TL;DR

This paper presents a compact, cost-effective method for laser frequency stabilization using a crystalline MgF2 whispering gallery mode microresonator, achieving sub-kHz linewidths and tunability within a high-finesse supercavity.

## Contribution

It introduces a novel stabilization technique combining microresonators with an extended cavity diode laser for enhanced frequency stability.

## Key findings

- Laser linewidth reduced to sub-kHz levels.
- Achieved stable Pound-Drever-Hall error signals.
- Demonstrated tunability over a large bandwidth.

## Abstract

We demonstrate a simple, compact, and cost-effective laser noise reduction method for stabilizing an extended cavity diode laser to a 3x105 finesse mirror Fabry-P\'erot (F-P) cavity corresponding to resonance linewidth of 10 kHz using a crystalline MgF2 whispering gallery mode microresonator (WGMR). The laser linewidth is reduced to sub-kHz such that a stable Pound-Drever-Hall (PDH) error signal is built up. The wavelength of the pre-stabilized laser is tunable within a large bandwidth covering the high reflection mirror coating of a F-P supercavity.

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Source: https://tomesphere.com/paper/1703.01259