Number Enhancement for Compact Laser-Cooled Atomic Samples by use of Stimulated Radiation Forces
Elizabeth A. Donley, Tara C. Liebisch, Eric M. Blanshan, John E. Kitching
For cold samples of laser-cooled atoms to be most useful in emerging technologies such as compact atomic clocks and sensors, it is necessary to achieve small sample sizes while retaining a large number of cold atoms. We consider achieving large atom numbers in a small system is a major challenge for producing miniaturized laser-cooled atomic clocks, since the number of captured atoms in a vapor-cell magneto-optical trap (MOT) scales as the fourth power of the laser beam diameter. This strong dependence on size is fundamentally set by the maximum spontaneous light force hbar k gamma /2, where hbar k is the photon momentum and gamma /2 is the maximum spontaneous photon scatter rate of a saturated transition of linewidth gamma. We are attempting to surmount the fundamental limit imposed by spontaneous emission by using bichromatic cooling, which is a technique that uses stimulated emission to slow the atoms. We have built a table-top experiment that uses stimulated-emission bichromatic cooling to pre-cool atoms and dramatically enhance the trappable atom number in a small MOT. We have designed the apparatus in a way that will let us test how bichromatic cooling scales with miniaturization. Here we report on our first experimental results of cooling a thermal beam of Rubidium atoms down to MOT capture velocities.
, Liebisch, T.
, Blanshan, E.
and Kitching, J.
Number Enhancement for Compact Laser-Cooled Atomic Samples by use of Stimulated Radiation Forces, Proc. 2010 Intl. Freq. Cont. Symp., Newport Beach, CA, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=905990
(Accessed September 17, 2021)