United States Patent
US Patent 5615558: Optical cooling of solids
US 5615558 · granted 1997-04-01
| Patent Number | 5615558 |
|---|---|
| Title | Optical cooling of solids |
| Filed | 1995-09-25 |
| Granted | 1997-04-01 |
| Inventor(s) | Eric A. Cornell, Michael J. Renn |
| Assignee | Individual |
| CPC Classification | F25B23/00, F25B1/00, F25B23/003 |
| Number of Claims | 3 |
Abstract
A device and method for laser cooling of a solid to extremely low temperature is disclosed, the device including an active cooling structure having a high purity surface passivated direct band gap semiconductor crystal of less than about 3 microns thick and a transparent hemispherical body in optical contact with the crystal. The crystal is itself cooled when illuminated with a laser beam tuned to a frequency no greater than the band gap edge frequency of the crystal. Cooling is caused by emission of photons of higher energy than photons entering the crystal, the additional energy being accounted for by process of absorption of thermal phonons from the crystal lattice.
Claims Summary
1. A device which is cooled by illumination with a laser beam of selected frequency, said device comprising:a high purity semitransparent crystal; and