Quantitative rainbow schlieren deflectometry.

In the rainbow schlieren apparatus, a continuously graded rainbow filter is placed in the back focal plane of the decollimating lens. Refractive-index gradients in the test section thus appear as gradations in huerather than irradiance. Asimple system is described wherein a conventional color CCD array and video digitizer are used to quantify accurately the color attributes of the resulting image, and hence the associated ray deflections. The present system provides a sensitivity comparable with that of conventional interferometry, while being simpler to implement and less sensitive to mechanical misalignment.

Compact color schlieren optical system.

A compact optical system for use with rainbow schlieren deflectometry is described. Both halves of the optical system consist of well-corrected telescopes whose refractive elements are all from manufacturer's stock catalogs, with the reflective primary being a spherical surface. As a result, the system is relatively easy to construct and meets the requirement of long focal length for quantitative rainbow schlieren measurements.

Veiling glare reduction methods compared for ophthalmic applications.

Veiling glare in ocular viewing was simulated by viewing the retina of an eye model through a sheet of light-scattering material lit from the front. Four methods of glare reduction were compared, namely, optical scanning, polarized light, viewing and illumination paths either coaxial or intersecting at the object, and closed circuit TV. Photographs show the effect of these methods on visibility. Polarized light was required to eliminate light specularly reflected from the instrument optics. The greatest glare reduction was obtained when the first three methods were utilized together. Glare reduction using TV was limited by nonuniform distribution of scattered light over the image.

Lens projection system for a solar simulator providing irradiance of 100 solar constants.

Algebraic design equations were derived for an optical projection system that included lenticular plates and a collimating lens. The system was applied to a solar simulator using a 20-kW xenon lamp. It produced an irradiance of 100 solar constants that was uniform to 1% within the volume of space occupied by a test model whose dimensions were of the order of 10 cm.

Optics at the lewis research center.

A survey is presented of the applications of optics to research at the NASA Lewis Research Center. The Center's principal research areas are flight propulsion and space power generation; these use optical devices and techniques in photography, gas density visualization, pyrometry of gases and surfaces, radiativeheat transfer studies, spectroscopy, spectroradiometry, solar simulation, and solar-cell development for space applications.