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WGM-Resonator/Tapered-Waveguide White-Light Sensor Optics

Light patterns formed by these optics contain information on absorption spectra. Theoretical and experimental investigations have demonstrated the feasibility of compact white-light sensor optics consisting of unitary combinations of (1) low-profile whisperinggallery- mode (WGM) resonators and (2) tapered rod optical waveguides. These sensors are highly wavelength-dispersive and are expected to be especially useful in biochemical applications for measuring absorption spectra of liquids.

Posted in: Physical Sciences, Briefs, TSP

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Raman-Suppressing Coupling for Optical Parametric Oscillator

Loading of desired modes is reduced, relative to loading of undesired modes. A Raman- scattering- suppressing input/ output coupling scheme has been devised for a whispering-gallery- mode optical resonator that is used as a fourwave- mixing device to effect an all-optical parametric oscillator. Raman scattering is undesired in such a device because (1) it is a nonlinear process that competes with the desired nonlinear four-wave conversion process involved in optical parametric oscillation and (2) as such, it reduces the power of the desired oscillation and contributes to output noise.

Posted in: Physical Sciences, Briefs, TSP

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Optical Magnetometer Incorporating Photonic Crystals

Sensitivity would be increased by orders of magnitude. According to a proposal, photonic crystals would be used to greatly increase the sensitivities of optical magnetometers that are already regarded as ultrasensitive. The proposal applies, more specifically, to a state-of-the-art type of quantum coherent magnetometer that exploits the electromagnetically- induced-transparency (EIT) method for determining a small change in a magnetic field indirectly via measurement of the shift, induced by that change, in the hyperfine levels of resonant atoms exposed to the field.

Posted in: Physical Sciences, Briefs

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A Panoramic View



Posted in: Blog

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Innovate and Win!

Have you entered your unique invention in the 2007 Create the Future Design Contest, presented by SolidWorks Corp. and NASA Tech Briefs? If not, you only have until October 15 to submit your design idea. Entries are being accepted in six categories: Machinery, Equipment, and Component Technology; Consumer Products; Medical; Safety and Security; Transportation; and Sustainable Technologies. All entries must be received by October 15, 2007, so submit your design idea today. Go here for guidelines and the official entry form.

Posted in: Blog

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Low VOC Binder/Resin System

Technology is required to reduce volatile organic compounds (VOCs) in binder/resins while maintaining or enhancing existing product properties. Potential solutions could include the addition of a compound or additive that reduces VOC demand, a new crosslinking system for polymers to enhance molecular network formation, or another technical solution that eliminates the existing issues with the low VOC resins currently available, such as poor appearance and high viscosity during drying (as typically encountered in a water borne approach), or slow drying and high application viscosity (as typically encountered in high-solids paints).

Posted in: NASA Tech Needs

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Rapid DC Magnetron Sputtering

DC magnetron sputtering provides a very durable and stable coating that has many high-energy laser (HEL) and industrial applications, especially in producing coatings for high-reflectivity (HR) mirrors and anti-reflection (AR) coated windows. However, the DC magnetron sputtering deposition process is extremely slow. This slow deposition results in long coating run times that translate into increased coating cost. An organization wants to reduce magnetron sputtering deposition times from 17 hours to 2 or 3 hours, while meeting current coating performance requirements. Coatings must meet MIL-C- 48497A environmental requirements.

Posted in: NASA Tech Needs

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