Beam deflector and scanner

Abstract

A beam deflector comprising a pair of mated microprism arrays with one of the arrays comprised of a variable refractive index material capable of being selectively changed in response to a field whose magnitude or intensity is regulated by regulating voltage applied. The other array preferably is comprised of a material having a constant refractive index. A conductive layer is disposed on both sides of the variable refractive index array. A pane preferably is disposed in front and behind the arrays. Two pairs of the arrays can be arranged parallel to each other with their microprisms generally perpendicular forming a two-dimensional deflector. To achieve a deflection response time faster than 100 &mgr;s, each prism has a height no larger than about 20 &mgr;m and a width preferably no greater than about 100 &mgr;m. Preferably, each prism height is less than about 15 to about 10 &mgr;m to achieve a response time 30 &mgr;s or faster. A method of making the deflector includes using direct-write electron beam lithography to make a master for replicating arrays having a height of 10 &mgr;m or less. A pair of deflectors can be used to deflect a beam in two dimensions and can be used in a scanner. Where the beam is a laser, the deflector can be used in a laser imaging radar assembly. Such a scanner and laser imaging radar assembly provide fast scanning of an object or region advantageously without requiring the deflector to move during scanning.