A new technique for laser cooling with superradiance

TL;DR

This paper proposes a theoretical laser cooling method using optical super-radiance in rare earth doped solids, promising faster cooling rates and overcoming host material limitations.

Contribution

It introduces a novel super-radiance based scheme for laser cooling of rare earth doped solids, enhancing cooling efficiency beyond traditional methods.

Findings

Super-radiance intensity scales with the square of excited ions

Cooling rate can be dramatically increased using SR

Overcomes limitations of low phonon energy hosts

Abstract

We present a new theoretical scheme for laser cooling of rare earth doped solids with optical super-radiance (SR), which is the coherent, sharply directed spontaneous emission of photons by a system of laser excited rare earth ions in the solid state host (glass or crystal). We consider an Yb3+ doped ZBLAN sample pumped at the wavelength 1015 nm with a rectangular pulsed source with a power of ~433W and duration of 10ns. The intensity of the SR is proportional to the square of the number of excited ions. This unique feature of SR permits a dramatic increase in the rate of the cooling process in comparison with the traditional laser cooling of the rare earth doped solids with anti-Stokes spontaneous incoherent radiation (fluorescence). This scheme overcomes the limitation of using only low phonon energy hosts for laser cooling.