A tunable Doppler-free dichroic lock for laser frequency stabilization

TL;DR

This paper introduces a tunable Doppler-free dichroic lock (TDFDL) technique for laser frequency stabilization, enabling wide-range lock point tuning without sacrificing signal slope, demonstrated using rubidium atom cooling lasers.

Contribution

The paper presents a novel TDFDL method that allows adjustable lock points in laser stabilization, improving flexibility over existing techniques.

Findings

TDFDL provides a wide tuning range for lock points.

The method maintains a high slope in the locking signal.

Effective for stabilizing MOT lasers for $^{87}Rb$ atoms.

Abstract

We propose and demonstrate a laser frequency stabilization scheme which generates a dispersion-like tunable Doppler-free dichroic lock (TDFDL) signal. This signal offers a wide tuning range for lock point (i.e. zero-crossing) without compromising on the slope of the locking signal. The method involves measurement of magnetically induced dichroism in an atomic vapour for a weak probe laser beam in presence of a counter propagating strong pump laser beam. A simple model is presented to explain the basic principles of this method to generate the TDFDL signal. The spectral shift in the locking signal is achieved by tuning the frequency of the pump beam. The TDFDL signal is shown to be useful for locking the frequency of a cooling laser used for magneto-optcal trap (MOT) for $^{87}Rb$ atoms.