Loading patent…
AssigneeThe Secretary of State for Defence in Her Brittanic Majesty's Government of the United Kingdom of Great Britain and Northern Ireland
InventorNorman Apsley
Estimating the term…
An electro-optical device is arranged as a Fabry Perot etalon comprising two mirrors and a central region. The mirrors are multilayer heterostructures of Al.sub.x Ga.sub.1-x As semiconductor materials where x alternates between 1.0 and 0.3. The central region may be a multiple quantum well structure of Al.sub.x Ga.sub.1-x As where x alternates between 0 and 0.3. The etalon material doping is non-uniform so that it is electrically a semiconductor device with a biasable central region. The optical path length in the central region is electric field dependent, and the etalon transmission or reflection is accordingly modulatable by varying the central region bias. The mirrors may be heavily doped and of opposite conductivity type with the central region undoped. This provides a PIN diode. Light incident on the etalon executes multiple transits of the central region. It is therefore unnecessary to employ long path lengths and high fields to enhance weak electro-optical effects in order to produce significant modulation, this being necessary in prior art devices.
In an electro-optical device comprising a Fabry-Perot etalon having a central region of electro-optic material between two mirrors of multilayer construction, and electrical biasing means, connected to the mirrors, for applying a variable bias to the mirrors to vary the refractive index of the central region and thereby the etalon fringe maximum wavelength, the improvement wherein:
In an electro-optical device comprising a Fabry-Perot etalon having a central region of electro-optic material between two mirrors of multilayer construction, and electrical biasing means, connected to the mirrors, for applying a variable bias to the mirrors to vary the central region refractive index and thereby the etalon fringe maximum wavelength, the improvement wherein:
Dependencies are inferred from the claim text.