Nick Wagner with Kathy Kash

Laser Trapping and Cooling

The use of lasers to trap and cool neutral atoms has attained temperatures in the millikelvin range. These cold atoms have allowed for high-resolution spectroscopy, increased the accuracy of atomic clocks, and are used to make Bose-Einstein condensates.  We intend to build a laser trapping and cooling apparatus, that has been described in literature, for use in Senior Lab. This involves building external cavity diode lasers and associated electronics for locking the frequency on to atomic absorption lines. In the process, we will perform detailed laser spectroscopy on rubidium around 780nm to determine the energy levels used for trapping.  Rubidium atom will then be trapping in a UHV chamber using two diode lasers: one to excite the trapping transition and one for hyperfine pumping. Once the trap is working, the fill rate and capacity of the trap can be measured as a function of laser power, laser polarization, and rubidium pressure.  The cooled and trapped atom can be bounced off a magnetic field to demonstrate the quantization of angular momentum, or further cooled in a magnetic trap.