DAVLL Magnetic Cell Holder

Here is a a mount for a Rb cell that can be used for dichroic atomic vapor laser lock (DAVLL) and spectroscopy of gasses in vapor cells. See http://iopscience.iop.org/article/10.1088/0953-4075/40/1/017/meta or other articles about DAVLL for more detail about the physics. Essentially the concept is that a magnetic field will split the atomic transitions of two states. Then by using the proper circularly polarized light and a beam splitter and absorption profile that is linear and crosses zero very close to resonance. This allows one to lock to the transition with out the use of modulating the signal and a lock-in amplifier.

The mount is designed for a OD 25 mm vapor cell. The holder has 6 squared slots that will hold 1/4" x 1/4" x 1/4" permanent rare-earth magnets. In each slot 12 magnets are inserted. They are kept in place with either one of the holders or lab tape. The magnets should be arranged in order to create an axial field. The DAVLL signal is visible with two, four, and six magnet stacks installed as seen from the attached plot. The plot shows a standard absorption spectra and the DAVLL spectra taken with a DBR whose wavelength/frequency is swept across the spectra.

The print was done with magnetic Iron PLA to enhance the field, but we found that the enhancement wasn't critical and the same spectra can be obtained with a standard PLA print.