Laser cooling and slowing of CaF molecules

TL;DR

This paper reports on the successful laser cooling and slowing of CaF molecules using resonant laser light, achieving deceleration, reduced velocity spread, and lower temperature, advancing molecular control techniques.

Contribution

It demonstrates for the first time the combined use of fixed-frequency and chirped laser light to slow and cool CaF molecules in a controlled manner.

Findings

Decelerated CaF molecules by about 20 m/s

Reduced velocity spread to achieve ~300 mK temperature

Implemented frequency chirping to enhance slowing efficiency

Abstract

We demonstrate slowing and longitudinal cooling of a supersonic beam of CaF molecules using counter-propagating laser light resonant with a closed rotational and almost closed vibrational transition. A group of molecules are decelerated by about 20 m/s by applying light of a fixed frequency for 1.8 ms. Their velocity spread is reduced, corresponding to a final temperature of about 300 mK. The velocity is further reduced by chirping the frequency of the light to keep it in resonance as the molecules slow down.