Raman spectroscopy is a subtle, but powerful technique for the characterization of surfaces and coatings. This laser-based technique probes the vibrational states of a materiel. Inelastic scattering of the incident laser beam results in frequency shifts in the scattered spectrum which are equal to… More

A unique method for producing very stable, sub-angstrom wide, reflection notch, and bandpass filters, with high optical rejection is proposed. This method takes advantage of a subtle process observed in vacuum ultra-violet (VUV) lithographic systems using fused silica optics known as, laser induced… More

Rugate Technologies, Incorporated, proposes to develop improved narrow notch and tunable Rugate filters for the infrared. Four problems are addressed in this study: (1) identification of Rugate material pairs for use in the far infrared (out to 30 microns); (2) development of polarization and… More

Rugate Interference filters are ideally suited to hyperspectral applications due to their ability to combine multiple functions and spectral regions in a single element, their flexible design and manufacture techniques, and their superior performance. Rugate transmission notches can be placed… More

Dense wavelength division multiplexing (DWDM) is dramatically increasing the bandwidth on telecommunications networks and will have a direct impact on internet-based communication architecture for data delivery from NASA near-earth platforms. The optical demultiplexers in DWDM systems rely on… More

Fabrication of far infrared notch filters requires development of a filter that is ten times thicker than our current near-infrared filters. Rugate Technologies proposes to improve upon its capability in infrared filter fabrication through incorporatingmultiple design techniques, materials… More

Fabrication of narrow band, far infrared (FIR), high reflectivity optical elements (notch filters) requires development of an interference filter that is approximately ten times thicker than standard FIR interference filters. In Phase I we developed designs capable of meeting 2% bandwidth FIR… More

This program will develop a cost effective, highly repeatable process for fabricating spatially variable neutral density filters with very tight geometry. Three fabrication methods will be developed and evaluated. The first method consists of sputtering through a moving deposition mask. The mask is… More

The feasibility of radioisotope thermophotovoltaic (RTPV) power systems has been shown. The best efficiencies reported to date for a TPV module test include front surface spectral control filters. This program will address the technical challenges to developing and qualifying highly efficient… More

The technical challenge of imaging planets in other star systems is resolving these dim objects in the close vicinity of a bright star. This challenge requires the suppression of direct and scattered light from the star without attenuating or distorting the planet's image. We will develop and… More

Sensor performance for the 3rd Generation FLIRs can be substantially improved by increased simultaneous throughput of both sensor bands in the optical systems. Currently available antireflection coatings (ARs) have optimized performance for either spectral band, but not both on the same optic. … More

Anti-reflection coating of ogive shaped optics presents a number of technical challenges. The principle challenge is obtaining a uniform high transmission coating on a strongly curved surface. The coating must perform well over a wide range of angles. If the optic is exposed to ambient conditions,… More

Sensor performance for the 3rd Generation FLIRs can be substantially improved by increased simultaneous throughput of both mid wave (MWIR) and long wave (LWIR) sensor bands (3.5 - 5m and 7.8 - 10.5m) in the optical systems. Phase I addressed coating design and initial deposition for five of… More

ABSTRACT: Optical filters on solar cells can improve cell performance by maximizing light transmission into the cell and by helping maintain cell operating temperature with minimal added weight. Anti-reflection films reduce Fresnel reflection losses and maximize light transmitted to the cell.… More