Accession Number : ADD012192

Title :   Picosecond Bistable Optical Switch Using Two-Photon Transitions.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Hoffman,Craig A ; Meyer,Jerry R ; Bartoli,Filbert

Report Date : 17 Dec 1985

Pagination or Media Count : 9

Abstract : This patent discloses 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 to 1 of 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.

Descriptors :   *PATENTS, *BISTABLE DEVICES, *SEMICONDUCTORS, *OPTICAL SWITCHING, *FABRY PEROT INTERFEROMETERS, NONLINEAR SYSTEMS, RESONATORS, RECOMBINATION REACTIONS, BAND THEORY OF SOLIDS, REFRACTIVE INDEX, OPTICAL PROPERTIES, CHARGE CARRIERS, TRANSMITTANCE

Subject Categories : Optics
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE