Absolute frequencies of H13C14N hydrogen cyanide transitions in 1,5 {\mu}m region with saturated spectroscopy and sub-kHz scanning laser

TL;DR

This study precisely measured the absolute frequencies of H13C14N hydrogen cyanide transitions in the 1.5 μm region using saturated spectroscopy and a stabilized laser, achieving unprecedented accuracy and resolution.

Contribution

First-time determination of H13C14N transition frequencies in the 1.5 μm range with sub-kHz precision using advanced laser stabilization and saturated spectroscopy techniques.

Findings

Achieved fractional uncertainty of 1.3e-10 in frequency measurements

Demonstrated fourtyfold improvement in spectral line resolution

Developed a method to stabilize low-pressure conditions for saturated spectroscopy

Abstract

The wide span and high density of lines in its rovibrational spectrum render hydrogen cyanide a useful spectroscopic media for referencing absolute frequencies of lasers in optical communication and dimensional metrology. We determined, for the first time to the best of our knowledge, the molecular transitions' center frequencies of the H13C14N isotope in the range from 1526 nm to 1566 nm with 1,3e-10 fractional uncertainty. We investigated the molecular transitions with a highly coherent and widely tunable scanning laser that was precisely referenced to a Hydrogen maser through an optical frequency comb. We demonstrated an approach to stabilize the operational conditions needed to maintain the constantly low pressure of the hydrogen cyanide to carry out the saturated spectroscopy with the third-harmonic synchronous demodulation. We demonstrated approximately a fourtyfold improvement in the line centers' resolution compared to the previous result.