Frequency-modulation saturation spectroscopy of molecular iodine hyperfine structure near 640 nm with a diode laser source

TL;DR

This paper demonstrates high-precision measurement of molecular iodine hyperfine structure near 640 nm using frequency-modulation saturation spectroscopy with a diode laser, achieving sub-MHz accuracy in frequency difference determination.

Contribution

It introduces a method for precise hyperfine structure measurement using a single diode laser and frequency modulation, improving accuracy and simplicity over previous techniques.

Findings

Hyperfine components measured with better than 0.1 MHz accuracy

Effective use of frequency modulation for hyperfine spectroscopy

Single laser setup simplifies high-precision measurements

Abstract

In a frequency-modulation spectroscopy experiment, using the radiation from a single frequency diode laser, the spectra of molecular iodine hyperfine structure near 640 nm were recorded on the transition $B^3\Pi_{0_u^{+}}-X^1\Sigma^+_{g}$. The frequency reference given by the value of the modulation frequency (12.5 MHz in given experiment) allows determination of the frequency differences between hyperfine components with accuracy better than 0.1 MHz using the fitting procedure in experiment with only one laser.