A flying spot mirror at 94GHz

The authors present the theoretical and experimental properties of a flying spot mirror (FSM) designed for operation at 94 GHz. The spatial domain of the mirror is a planar array of I-poles, each center-loaded with a small element of switchable, thin-film vanadium dioxide (VO/sub 2/). VO/sub 2/ undergoes a thermally induced semiconductor-to-metal phase transition near 65/spl deg/, which is accompanied by dramatic changes in electric and optical properties. If the conductance of the VO/sub 2/ film is changed from low (cold state) to high (hot state) over a 10/sup 4/ range, a surface reflectance variation of the mirror from 1% to 94% is predicted. A diffraction-limited area, or pixel, contains about thirty I-poles. The flying scheme is obtained by suitably programming the switching of the individual pixels. >