Paul M. Zavracky

Transparent heat‐mirror films of TiO2/Ag/TiO2 for solar energy collection and radiation insulation

Transparent heat‐mirror films of TiO2/Ag/TiO2 on glass with a visible transmission of 84% (at 0.5 μm) and an infrared reflectivity of 98–99% (at 10 μm) have been fabricated by rf sputtering. Initial tests indicate that the films are thermally stable in air at 200°C and inert to water attack. Because of their excellent optical properties and apparent stability, these transparent heat‐mirror films offer great promise for use in solar‐thermal power conversion and as transparent thermal insulators.

Selective black absorbers using MgO/Au cermet films

Cermet MgO/Au films prepared by rf sputtering are found to be highly absorbing in the solar spectrum and highly transparent in the infrared. Excellent selective absorbers, with solar absorptivity of over 0.9 and infrared emissivity of less than 0.1, have been produced by depositing such films on metal substrates. Films deposited on Mo‐coated stainless steel are stable in air up to 400u2009°C.

Thin‐film VO2 submillimeter‐wave modulators and polarizers

Submillimeter‐wave modulators and switchable polarizers have been fabricated from VO2 thin films deposited on sapphire substrates. By passing electric current pulses through elements made from these films, the films can be thermally cycled through the insulator‐to‐metal transition that occurs in VO2 at about 65u2009°C. In the insulating state, the films are found to have negligible effect on the transmission at submillimeter wavelengths, while above the phase transition the transmission is strongly reduced by the free‐electron effects characteristic of a metal. Other possible applications of such switchable VO2 elements include variable bandpass filters and diffraction grating beam‐steering devices.

Video I/O interface for wearable computers

This paper is a report of work in progress toward the development and testing of a computer interface mounted in eyewear, and capable of both input and output functions. The unique feature of this interface is the use of advanced embedded optical techniques to form eyeglass lenses capable of relaying images internally, without significant optical components in front of the users face. These optical techniques make possible the incorporation of both a camera and display within eyeglasses. The interface also includes audio input and output. The paper discusses methods of constructing such an interface, design considerations, and will describe work in progress to realize working models.

Eyewear-based displays for personal electronics

This paper addresses the development of eyewear based displays for portable, personal electronics. The personal electronic system applications include the wearable personal computer, portable digital video disk player, and the cellular telephone. We describe progress on integrated eyewear systems, as well as on clip-on systems that can attach to ordinary eyewear. We conclude with a short description of a system that will include a camera, display, and audio system.

P‐16: Wearable, Stereo Eyewear Display

This paper reports the successful construction and demonstration of a lightweight wearable stereoscopic display. The imaging element is an active matrix liquid crystal display. The optics are specially designed for wearable, portable applications and comprise a color corrected refractive magnifying system. The diagonal field of view of the VGA system is 20 degrees.