A frequency quintupled laser at 308 nm for spectroscopy of intercombination lines in zinc

TL;DR

This paper presents a novel, portable, continuous wave laser at 308 nm with low noise, achieved through frequency quintupling of a telecom-band fiber laser, enabling precise spectroscopy of zinc's intercombination lines.

Contribution

The authors developed a robust, transportable 308 nm cw laser using frequency quintupling from a fiber laser, suitable for atomic physics and quantum optics applications.

Findings

Achieved 0.5 mW output power at 308 nm

Demonstrated laser performance via zinc spectroscopy

Utilized three nonlinear crystal stages for frequency conversion

Abstract

Many experiments in atomic physics and quantum optics, among them optical atomic clocks, require laser sources in the ultra-violet wavelength range with very low intensity noise and phase noise. The development of such lasers is a challenge, especially when a robust and transportable system is required. Here, we report on the development of a novel continuous wave (cw) frequency-quintupled laser at 308 nm with an output power of 0.5 mW, based on a fiber laser operating in the telecom band. Three consecutive frequency conversion stages in nonlinear crystals are employed. The performance of the laser system is demonstrated by linear absorption spectroscopy of a narrow intercombination line in zinc.