Laser cooling system for caesium.
Ley, Li Yuan.
Date of Issue2012
School of Physical and Mathematical Sciences
In this final year project, a laser system was built for cooling 133Cs. We build 2 external cavity diode lasers (ECDL) at 852nm, serving as the lasers for cooling and repumping of 133Cs. The power from one of the ECDL was ampli ed with a tapered ampli er(TA) in the master oscillator power ampli er (MOPA) con guration. Both lasers are frequency stabilized to within 1MHz by two di erent techniques: AC locking using saturated absorption spectroscopy, and trombone locking using beat signal. Then acousto-optic modulators (AOM) are used to o set and ne tune the frequency of the various lasers beam required for the cooling experiment. All electronics that required for stabilizing laser were hand build, this include current controller, temperature controller, AOM controller, COSY box driver, PI controller and Log-in ampli er. A compact con guration of Doppler free saturation spectroscopy(COSY box) use in AC locking was also designed and hand build by author. The 133Cs cooling system setup and laser stabilization will be discuss in this thesis.
Final Year Project (FYP)