A high-power 626 nm diode laser system for Beryllium ion trapping

TL;DR

This paper presents a cost-effective, high-power, tunable diode laser system at 626 nm designed for efficient Beryllium ion trapping, utilizing thermoelectric cooling and injection locking to enhance power and stability.

Contribution

It introduces a novel laser setup combining thermoelectric cooling and injection locking to achieve high power and tunability at 626 nm for Beryllium ion trapping applications.

Findings

Achieved approximately 130 mW power near 626 nm.

Demonstrated effective injection locking for power enhancement.

Provided a simplified, low-cost laser solution for ion trapping.

Abstract

We describe a high-power, frequency-tunable, external cavity diode laser (ECDL) system near 626 nm useful for laser cooling of trapped $^9$Be$^+$ ions. A commercial single-mode laser diode with rated power output of 170 mW at 635 nm is cooled to $\approx - 31$ C, and a single longitudinal mode is selected via the Littrow configuration. In our setup, involving multiple stages of thermoelectric cooling, we are able to obtain $\approx$130 mW near 626 nm, sufficient for efficient frequency doubling to the required Doppler cooling wavelengths near 313 nm in ionized Beryllium. In order to improve nonlinear frequency conversion efficiency, we achieve larger useful power via injection locking of a slave laser. In this way the entirety of the slave output power is available for frequency doubling, while analysis may be performed on the master output. We believe that this simple laser system addresses a key need in the ion trapping community and dramatically reduces the cost and complexity associated with Beryllium ion trapping experiments.