Ltv Aerospace and Defense

Arthur E Sobey, Jr

Apparatus for rapidly erasing and rebiasing a thermoptic thin film in the near and medium infrared. A thermal insulating material (56) is disposed adjacent a thermoptic vanadium oxide thin film (50). The insulating layer has high transmittance in the 3-5 or 8-12 micrometer spectral bands. A layer of resistive semiconductor material (54) having high transmittance in the 3-5 or 8-12 micrometer band is disposed between the layer of insulating material and the vanadium oxide thin film. A multilayer dielectric thin film stack is superposed adjacent the vanadium oxide thin film, or is disposed in two parts adjacent the upper and lower surfaces of the thermoptic thin film. The multilayer dielectric stack, in combination with the thermoptic film, the resistive layer and the insulating layer provides a low reflectance, high transmittance condition over the 3-5 or 8-12 micrometer band when the thermoptic film is in its semiconducting state and a high reflectance condition over the same band when the thermoptic film is in its metallic state. The resistive layer is connected to a current generator (18) which supplies a current to the resistive layer dissipating heat into the vanadium oxide thin film and into the insulating layer. A thermal body (24), having high thermal conductivity and interfacing with the insulating layer at the opposite boundary from the thermoptic thin film, contains a conduit (34) through which a refrigerated liquid (26) is flowed to establish a thermal gradient from the thermoptic thin film to the fluid.

Growing community of inventors

Richardson, TX, United States of America

Arthur E Sobey, Jr