Noise reduction of a Libbrecht--Hall style current driver

TL;DR

This paper investigates the noise increase in the Libbrecht--Hall current driver near its current limit and proposes simple circuit modifications to reduce this noise, improving laser stability.

Contribution

It identifies the noise behavior near the current limit and introduces circuit modifications to mitigate this issue, enhancing the driver’s performance.

Findings

Noise increases dramatically near current limit

Circuit modifications can reduce noise

Improved laser current stability

Abstract

The Libbrecht--Hall circuit is a well-known, low-noise current driver for narrow-linewidth diode lasers. An important feature of the circuit is a current limit to protect the laser diode. As the current approaches the maximum limit, however, the noise in the laser current increases dramatically. This paper documents this behavior and explores simple circuit modifications to alleviate this issue.