Spectroscopy of AlCl at 261nm for Laser Cooling and Trapping

Ultra-cold dipolar molecules offer platforms for precision measurements of fundamental constants, quantum computation, study of ultracold chemistry and other novel physics. Aluminum mono-chloride (AlCl) has been proposed as a promising candidate for laser cooling and trapping. We use a frequency-tripled CW Titanium-Sapphire laser to do spectroscopy on AlCl generated via laser ablation of AlCl₃ and other precursors in a cryogenic helium buffer-gas beam source. The spectroscopy light is produced by first frequency-doubling 784nm to 392nm. The 392nm light is then combined with the fundamental in a sum-frequency process to create light at 261nm. Here, we discuss details of our molecular beam source and our laser system for generating UV light and we present our spectroscopy results for the X1Σ⁺ → A1Π transition in AlCl and our estimated Frank-Condon factors for the ν=0 →ν′ =0 and ν=1→ν′ =1 transitions. Furthermore, we present our results on investigating various precursors for producing AlCl.