Measurements on release-recapture of cold Rb-85 atoms using an optical nanofibre in a magneto-optical trap

TL;DR

This study uses an optical nanofibre in a magneto-optical trap to measure cold Rb-85 atom temperatures and trap properties, revealing effects of laser parameters and atom density on cooling efficiency and trap dynamics.

Contribution

It introduces a sensitive ONF-assisted release-recapture method for measuring atom temperatures and detecting optical misalignments in a MOT.

Findings

Onset of multiple scattering regime observed without cloud size estimation.

Temperature and trap spring constant vary with laser light-shift parameter.

Method detects optical misalignments effectively.

Abstract

We have performed release-recapture temperature measurements of laser-cooled Rb-85 atoms using an optical nanofibre (ONF) in a magneto-optical trap (MOT). The effects of changing the cooling laser light-shift parameter on the temperature of the cold atoms and spring constant of the trap are studied. By varying the cold atom number density near the ONF, the onset of the multiple scattering regime is observed without the need for an estimation of the atom cloud size. Moreover, this sensitive ONF assisted release-recapture technique is easily able to detect any optical misalignment of the cooling laser beams in the MOT.