Injection locking of a high power ultraviolet laser diode for laser cooling of ytterbium atoms

TL;DR

This paper presents a high-power ultraviolet laser system at 399 nm for laser cooling of ytterbium atoms, utilizing injection locking of laser diodes to achieve stable, high output power without complex nonlinear processes.

Contribution

The authors developed a systematic method for injection locking of ultraviolet laser diodes, enabling high-power, stable laser sources at 399 nm for atomic physics applications.

Findings

Achieved 220 mW output power at 399 nm through injection locking.

Provided a systematic optimization method applicable to other wavelengths.

Demonstrated potential for portable optical lattice clocks and quantum experiments.

Abstract

We developed a high-power laser system at a wavelength of 399 nm for laser cooling of ytterbium atoms with ultraviolet laser diodes. The system is composed of an external cavity laser diode providing frequency stabilized output at a power of 40 mW and another laser diode for amplifying the laser power up to 220 mW by injection locking. The systematic method for optimization of our injection locking can also be applied to high power light sources at any other wavelengths. Our system, which does not depend on complex nonlinear frequency-doubling, has great importance for implementing transportable optical lattice clocks, and is also useful for investigations on condensed matter physics or quantum information processing using cold atoms.