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We have designed, fabricated, and tested hybrid refractive/diffractive optical elements in acrylic and cyclic olefin copolymer polymers. The elements were tested for optical performance before and after various environmental conditions.

A diffractive optical surface was inserted in a wide field of view ultraviolet sensor to increase the aperture and waveband of the system with no increase in size or weight. The diffractive optical surface was etched in sapphire using binary optics fabrication techniques.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

This paper describes the fabrication and testing of 64 X 96 arrays of microlenses used for fill-factor enhancement of uncooled infrared detector arrays. Each lenslet represents a f/0.9 Fresnel phase lens at 10 micrometers wavelength. All arrays were etched into silicon wafers as either 8-level or 16-level staircase kinoforms. When integrated with a detector array having 20 fill factor, these microlens arrays were capable of increasing the magnitude of the measured signal with f/2.2 fore-optics by 2.5-fold.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

We examine the role of processing errors on diffraction efficiency of binary optical elements and the validity of the Fourier model to predict diffraction efficiency. We show that mask alignment error can significantly degrade efficiency. Models based on the Fourier theory can adequately predict both the magnitude of diffraction efficiency and its sensitivity to processing errors for optically slow elements (f/b). For optically fast elements (

The transition from a positive to a negative temperature coefficient of resistivity (TCR) has been studied in the artificially layered metallic system Nb-Cu. We find the TCR to undergo a rather sudden change in sign from positive to negative as the layer thickness is decreased below approximately 10 A. The temperature dependence of the conductivity in the nonmetallic regime can be explained by localization-type theories, and implies that both localization and Coulomb effects are important in this purely metallic three-dimensional system.