Frequency noise characterization of diode lasers for vapor cell clocks applications

TL;DR

This paper presents a technique to measure the frequency noise spectrum of diode lasers, which is crucial for optimizing vapor cell clock performance, filling a gap in existing measurement methods.

Contribution

A novel frequency-to-voltage conversion method for characterizing diode laser frequency noise across a wide frequency range.

Findings

Effective characterization of laser frequency noise spectrum

Technique applicable to vapor cell clock applications

Provides data rarely available from vendors

Abstract

The knowledge of the frequency noise spectrum of a diode laser is of interest in several high resolution experiments. Specifically, in laser-pumped vapor cell clocks, it is well established that the laser frequency noise plays a role in affecting the clock performances. It is then important to characterize the frequency noise of a diode laser, especially since such measurements are rarely found in the literature and hardly ever provided by vendors. In this paper, we describe a technique based on a frequency-to-voltage converter that transforms the laser frequency fluctuations into voltage fluctuations. In this way, it is possible to characterize the laser frequency noise power spectral density in a wide range of Fourier frequencies, as required in cell clock applications.