An intense, cold, velocity-controlled molecular beam by frequency-chirped laser slowing

TL;DR

This paper demonstrates a method to produce a cold, intense molecular beam of CaF using frequency-chirped laser slowing, achieving precise velocity control and high flux suitable for advanced quantum experiments.

Contribution

It introduces a novel frequency-chirped laser slowing technique for molecular beams, improving velocity control and flux retention over traditional methods.

Findings

Achieved molecular beam velocities down to a few m/s

Compressed velocity spread by a factor of 10

Measured flux of 7×10^5 molecules/cm^2 per shot at 15 m/s

Abstract

Using frequency-chirped radiation pressure slowing, we precisely control the velocity of a pulsed CaF molecular beam down to a few m/s, compressing its velocity spread by a factor of 10 while retaining high intensity: at a velocity of 15~m/s the flux, measured 1.3~m from the source, is 7$\times$10$^{5}$ molecules per cm$^{2}$ per shot in a single rovibrational state. The beam is suitable for loading a magneto-optical trap or, when combined with transverse laser cooling, improving the precision of spectroscopic measurements that test fundamental physics. We compare the frequency-chirped slowing method with the more commonly used frequency-broadened slowing method.