Power stabilization of a diode laser with an acousto-optic modulator

TL;DR

This paper demonstrates a method to stabilize diode laser power using an acousto-optic modulator, significantly reducing high-frequency noise and slow power fluctuations to improve device performance.

Contribution

The study provides an experimental approach to laser power stabilization with detailed noise reduction measurements across frequency and time domains.

Findings

Power noise reduced to 2.2×10⁻⁸ Hz⁻¹/² in 1-100 kHz range

Relative Allan deviation of 6×10⁻⁷ at 100 s

Instability increases to 2×10⁻⁶ at 10,000 s

Abstract

Laser power fluctuations can significantly reduce the device performances in various applications. High frequency fluctuations impact the signal-to-noise ratio, while slow variations can reduce the device repeatability or accuracy. Here we report experimental investigations on the power stabilization of a diode laser with an acousto-optic modulator. In the frequency domain the relative power noise is reduced at the level of $2.2\times 10^{-8}$ Hz$^{-1/2}$ in the range 1-100 kHz. The slow variations are studied in the time domain. The relative Allan standard deviation is measured at the level of $6\times 10^{-7}$ at 100 s averaging time. Above 100 s the instability increases and reaches $2 \times 10^{-6}$ at 10 000 s.