Laser frequency stabilization by modulation transfer spectroscopy and balanced detection of molecular iodine for laser cooling of ${}^{174}$Yb

TL;DR

This paper demonstrates a method for stabilizing laser frequency using modulation transfer spectroscopy and balanced detection of molecular iodine, enabling precise laser cooling of ytterbium-174 with reduced noise.

Contribution

It introduces a novel frequency stabilization technique combining modulation transfer spectroscopy and balanced detection on molecular iodine for laser cooling applications.

Findings

Achieved an on-resonance optical depth of 47 in the atomic cloud.

Reduced laser noise and characterized frequency stability with an Allan deviation of 3.9 x 10^{-13} at 0.17 s.

Established molecular iodine as a reliable frequency reference for ytterbium laser cooling.

Abstract

We report laser frequency stabilization by the combination of modulation transfer spectroscopy and balanced detection of a relatively weak hyperfine transition of the R(158)25-0 line of molecular iodine (${}^{127}$I$_{2}$), which is used as a new frequency reference for laser trapping and cooling of ${}^{174}$Yb on the $^{1}S_{0} - {}^{3}P_{1}$ transition. The atomic cloud is characterized by time-of-flight measurements, and an on-resonance optical depth of up to 47 is obtained. We show laser noise reduction and characterize the short-term laser frequency instability by the Allan deviation of the laser fractional frequency. The minimum measured value is 3.9 x $10^{-13}$ at 0.17 s of averaging time.