|MadSci Network: Physics|
Laser cooling systems use tunable lasers capable of matching the frequency of the atoms that are to be trapped. Typically, diode-lasers are used in this process. Diode-lasers are used for a number of reasons. They are low cost; which is an advantage where two lasers are used in the cooling process (one for trapping the atoms and another for optical repumping). Additionally, diode-lasers have excellent spectral properties and power stability. The disadvantage of the diode-laser is its low power (typically less than 50 mW). Several cooling experiments have used Ti- sapphire lasers, repumped with an Argon-ion laser. Even though these lasers are very costly, they have the advantage of having a high tuning rate and larger power output than a diode-laser. More power allows for a larger magneto-optical trap to be used in the laser cooling process. The efficiency of these laser-cooling systems is based on the cooling efficiency relative to the absorbed laser power. Reports on this efficiency range from approximately 0.5% to 2.0%. References: C.E. Mungen, et al., Appl. Phys. Lett. 71 (11) 15 September 1997. C. Zimmermann, et al., Opt. Lett. 20, 297 (1995). I. Shvarchuck, et al., Appl. Phys. B 71, 475-480 (2000). S.N. Atutov, et al., Phys. Rev. Lett. 80, 2129 (1998). R. I. Epstein, et al., Nature, 377, 500-503, 1995.
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