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Results for “Applied optics”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1968

Facilities office

Variable optical techniques applied to solar simulators

Source record↗
NASA NTRS1968

Polarons in anisotropic energy bands.

Polaron coupling approximation applied to electron-longitudinal optical phonon interaction on spheroidal energy band surface of strontium titanate

Kahn, A. H.↗
NASA NTRS1964

Plastic films for reflective surfaces reproduced from masters

Accurate reproduction in plastic of the surface of the optical master to which a reflective finish may be applied is done by using backing from any suitable material to which cured plastic will adhere tightly. Plastics used for reflectors should be of the thermosetting or catalytically hardened type.

Source record↗
NASA NTRS1959

Investigation of Spherical-Wave-Initiated Flow Fields Around Bodies

Measurements of the velocity flow fields and vortex movements have been made about various simple blunt models undergoing spherical blast waves with a positive overpressure of 4 pounds per square inch. A bullet-optical method was used to determine flow velocities and is applied to velocity fields in which the gradients are largely normal to the free-stream direction. The velocity flow fields are shown at various flow times following passage of the blast front for different models. Vortex movements with time are compared for square-bar models of various aspect ratios. Corner sharpness had no discernible effect on the overall disturbed velocity fields or vortex movements for the square-box models used.

McFarland, Donald R.↗
NASA NTRS1965

Electro-optic crystals and their use for light modulation

Several methods of modulating a beam of light, which have been described in the literature, utilizing the influence of an electrical signal on the birefringence of certain crystals, will be reviewed. These employ optics which respond to the state of polarization of a light beam, and include intensity modulation, position modulation, and the possibility of an electrically tuned optical filter. The influence of the piezo-optic, or strain contribution to the total electro-optic response in the design of an optoelectronic device will be discussed. Current experimental work in our laboratory in which the strain contribution is separated from the direct effect will be described. The strain-free effect is measured by applying a step voltage to the crystal, and observing the initial response. The electro-optical transient response can be observed with nanosecond time resolution. An electronic sampling technique is used to extract the desired response from photon noise. The stress-free or low-frequency effect is measured similarly but at low audio frequencies. Single crystal tetragonal BaT10 3 has been investigated in detail with the result that the strain-optic contribution to the low frequency effect r_(c) = r_(33)—r_(13) is about 80% of the total, where it is only 10% in KDP and 45% in ADP. The magnitudes of the electro-optic effect, dielectric constant, and other related properties are compared for several materials potentially useful as electro-optic modulators, and some comments are made about the practical problems of building a modulator.

ELECTRO-OPTICS↗