Anti-Stokes optical cooling is compared theoretically to Peltier cooling. T
he influence of reabsorption of fluorescence photons, parasitic absorption,
and interaction length is discussed by using a simple modeling for the pro
pagation of laser and fluorescence waves. An equivalence between anti-Stoke
s and Peltier coolings is presented, which shows that Peltier effect potent
ially exhibits a higher cooling coefficient but much larger thermal losses
than anti-Stokes fluorescence. As a consequence, Peltier coolers are shown
to be more effective for heat pump and high temperature operation (T > 190
K), while anti-Stokes coolers could be used down to low cooling temperature
s (around 70 K) especially if the cooling material could be operated at lon
g pump wavelength. Moreover, if photons emitted at the anti-Stokes frequenc
y are down converted to the laser frequency and recycled into the cooling m
edium, anti-Stokes cooling could reach very high efficiencies even in the l
ow temperature regime, making this technique highly attractive for cooling
down of small devices. (C) 2000 American Institute of Physics. [S0021-8979(
00)02204-0].