Picosecond bistable optical switch using two-photon transitions
US4558923A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1983 |
| Grant date | Dec 17, 1985 |
| Priority date | — |
| Expiry date | Dec 22, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02F3/024
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A bistable optical switch comprising a Fabry-Perot resonator containing a nonlinear semiconductor medium with a desired band structure and whose susceptibility (refractive index) varies with optical energy density. The Fabry-Perot resonator is biased to a point where two stable transmission states are possible. Switching is accomplished by pumping the nonlinear material with an energy hw in the range 1/2.DELTA..sub.g <hw<.DELTA..sub.g, where .DELTA..sub.g is the bandgap between the upper valence band and the conduction band of the nonlinear material, in order to stimulate a two-photon valence-to-conduction band absorption transition at a non-minimum energy and thereby make possible a one-hw photon virtual transition between the heavy hole and split-off valence bands of the nonlinear material. This virtual transition alters the susceptibility thereby switching the resonator to a different stable transmission state. Switching times on the order of picoseconds are obtained because switching-time is not dependent on the carrier recombination time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.