Diode Laser Stabilization: Iodine and Beyond

Stable optical frequency references are useful tools in an atomic, molecular, and optical (AMO) physics laboratory. We recently observed sub-Doppler resonance features in iodine using an external cavity laser diode system at ~637 nm. Using phase modulation techniques we produced an asymmetric error signal. We are currently building a suitable feedback loop (integrator) to lock the laser frequency to one of these features, thereby stabilizing to an absolute reference.
Currently, spectroscopic features have been observed around 637 nm. A future goal is to change to lasers corresponding to rubidium transitions with resonances around 780 nm. These lasers will be used to trap and cool the atoms. Cold atoms would enable precise rubidium spectroscopy and expand the AMO research capabilities of the laboratory.

- Paul Weavers, junior physics major