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Reflective displays that rely on ambient light as opposed to an internal light source have been making inroads for a variety of important applications, especially those involving mobility where power usage must be aggressively controlled. The underlying color rendering strategies for both reflective and emissive displays have largely been the same, combining three fixed, primary color subpixels to compose the rich gamut that users expect. The result, for reflective color displays, is unfavorable brightness/gamut performance since each of the color subpixels absorbs roughly 2/3 of the incident white light. We demonstrate a new technology that we call the single mirror interferometric display that overcomes such limitations with pixels whose reflectance properties can tune through a continuum of colors, including high contrast black and white reflectance states. We use an effect that we call interferometric absorption in which a thin absorbing metal layer in front of a highly reflective mirror surface selectively absorbs different colors, depending on the gap that separates the two. The gap is controlled by electrostatic actuation in a relatively simple micro-electro-mechanical-system structure. We describe this elegant and powerful color rendering principle and present experimental results for the basic pixel device as well as early system demonstrations.

We describe the lens design for a twin-imaging white-light interferometer in which the interference pattern at the exit-pupil plane is the cosine transform of the spatial-intensity distribution of the object. The achromatic condition in terms of optical power is derived. The analysis of the transform aberration shows that the even aberrations, e.g., spherical aberration and field curvature, do not degrade the cosine transform and need not be corrected. This significant simplification permits us to design systems with good performance and uncomplicated lens structures. We present a lens design with three elements and a length of 320 mm. The system is capable of resolving more than 10(6) pixels with an operating spectral bandwidth of 100 nm. The results of an experiment with an early four-element design are also presented.

Two-dimensional sine, cosine, and Fourier transforms are obtained for objects illuminated by spatially incoherent, bandlimited light. A lensless Fresnel zone processor consisting of a double-imaging interferometer, a CCD array, and a digital computer is described and analyzed. Excellent bias removal and shot-noise level performance are obtained using a 14-bit digitizer. Experimental optical transforms are presented for an offset circular aperture and for a binary zone plate transmittance. The space–bandwidth product is derived, and excellent comparison with experiment is obtained.

A novel sine-filter-cosine cascade is proposed that is realizable for either coherent or spatially incoherent illumination. Computer simulation is used to demonstrate effectively matched filter performance and elimination of deleterious background bias.