Laser cooling or optical cooling is based on the principle of anti-Stokes fluorescence. Lasers can be used to efficiently cool objects. Laser cooling research has advanced the field of optical cooling science and provided a basis for a future generation of novel refrigeration devices based on laser technology. Optical irradiation accompanied by spontaneous anti-Stokes emission can lead to cooling of matter, in the phenomenon of laser cooling, or optical refrigeration. Current cooling systems use refrigerant, which is harmful to the ozone layer, and these could be replaced by a revolutionary cooling system using lasers.

Concept of Laser Cooling

Laser Cooling To Cool Electronics Circuits at IC Semiconductor-levelLaser cooling occurs when the amount of energy emitted by a solid, when exposed to an energy source, is more than the energy it absorbs. In other words, a laser aimed at certain materials will excite the materials’ atoms to a higher energy state. These excited atoms absorb a little extra energy from the heat of the surrounding material. When they produce photons, the photons are of a higher energy than the initial laser energy and this radiation of energy cools the material.

In gaseous matter, an extremely low temperature can be obtained in diluted atomic gases by Doppler cooling, and laser cooling of ultradense gas has been demonstrated by collisional redistribution of radiation. The Doppler cooling limit of optical molasses can be derived by considering the balance between the rate at which atoms lose and gain kinetic energy while interacting with the cooling lasers.

Laser cooling and trapping techniques rely on selectively exciting transitions between atomic substates by controlling the polarization, propagation direction, and frequency of the laser light.

Laser Cooling Technologies/Methodologies List

Laser cooling can be achieved by a number of techniques in which atomic and molecular samples are cooled down to near absolute zero through the interaction with one or more laser light fields.

  • Doppler cooling of lasers
  • Cavity mediated cooling
  • Resolved sideband cooling
  • Anti-Stokes inelastic light scattering (typically in the form of fluorescence or Raman scattering)
  • Sisyphus cooling
  • Velocity selective coherent population trapping (VSCPT)
  • Sympathetic cooling
  • Use of a Zeeman slower

Laser Cooling for Electronics Circuits, and ICs at Semiconductor-level

Since laser coolers would be entirely solid-state devices, they would generate no vibrations and could survive unmaintained for years in the brutal environment of space.

In the future, laser cooling devices may even find uses in desktop computers where they could cool superconducting circuits, allowing the circuits to operate at speeds hundreds of times faster than today’s conventional electronics without overheating.

In solid-state materials, laser cooling is achieved by the annihilation of phonons, which are quanta of lattice vibrations, during anti-Stokes luminescence. Since the first experimental demonstration in glasses doped with rare-earth metals.

Laser cooling computer chips that cool on their own, minimising heat and thus prolonging battery life for portable devices like tablets and smart phones.