High passive-stability diode-laser design for use in atomic-physics experiments

TL;DR

This paper introduces a robust, cost-effective external cavity diode laser system with high passive stability and low spectral linewidth, suitable for atomic physics experiments, outperforming commercial systems in stability and noise reduction.

Contribution

The paper presents a novel diode-laser design with a single aluminum block cavity, vacuum sealing, and integrated noise isolation, offering improved passive stability and linewidth performance.

Findings

Performance exceeds published commercial specifications

Demonstrates high passive spectral stability

Achieves low linewidth suitable for precision experiments

Abstract

We present the design and performance characterization of an external cavity diode-laser system optimized for high stability, low passive spectral linewidth, low cost, and ease of in-house assembly. The main cavity body is machined from a single aluminum block for robustness to temperature changes and mechanical vibrations, and features a stiff and light diffraction-grating arm to suppress low-frequency mechanical resonances. The cavity is vacuum-sealed, and a custom-molded silicone external housing further isolates the system from acoustic noise and temperature fluctuations. Beam shaping, optical isolation, and fiber coupling are integrated, and the design is easily adapted to many commonly used wavelengths. Resonance data, passive-linewidth data, and passive stability characterization of the new design demonstrate that its performance exceeds published specifications for commercial precision diode-laser systems. The design is fully documented and freely available.