Optical cycling of MgF molecules within the hyperfine states in X(N=1) state

TL;DR

This study demonstrates enhanced optical cycling in MgF molecules by optimizing laser parameters, significantly increasing photon scattering rates, which advances laser cooling techniques for molecules.

Contribution

It introduces an optimized method for optical cycling in MgF molecules, improving photon scattering rates through multi-frequency laser application and magnetic field use.

Findings

Photon scattering rate increased by about six times under optimal conditions.

Simultaneous multi-frequency laser application enhances optical cycling efficiency.

Results support future laser cooling and trapping of MgF molecules.

Abstract

We investigated the optical cycling effect of the $\mathrm{X}^2\Sigma(v=0,\ N=1^-) - \mathrm{A}^2\Pi_{1/2}(v'=0,\ J'=1/2^+)$ band of MgF molecules, specifically the $\mathrm{P_1/Q_{12}(1)}$ transition, which serves as the main transition in the quasi-closed cycling scheme for the laser cooling. A higher number of scattered photons was observed when all three frequency components of the $\mathrm{P_1/Q_{12}(1)}$ transition were simultaneously applied using acousto-optic modulators (AOMs). Optimal conditions were identified by scanning the detuning of frequency components, the laser beam power ratio, and the total laser beam power, and the results were confirmed through rate equation simulations. Under these optimized conditions, and with an applied magnetic field, the scattering rate was enhanced by approximately a factor of six. These results refine the implementation of optical cycling in MgF and lay the groundwork for laser slowing and magneto-optical trapping (MOT) experiments.