The availability of high peak-power laser systems capable of delivering intense deep-UV pulses has brought renewed interest in using Raman spectroscopy as both a selective and sensitive analytical technique for stand-off detection. Our approach uses a high power pulsed-laser as the excitation source, specifically the fourth and fifth harmonics of a Nd:YAG laser. One of the hurdles to be overcome to allow deep-UV Raman spectroscopy to become accessible is a direct method of calibrating both the observation frequency and detector response of the spectrograph being used. This report outlines our efforts to understand the photochemical and photophysical consequences of high-peak power excitation of cyclohexane for potential use as a secondary Raman standard in the deep-UV. Evaluation of the photochemical stability, both from multi-photon absorption and in the presence or absence of dissolved oxygen as well as the possibility of (near) resonance enhancement of the C-H stretching region will be described.

The performance of optical and electronic detectors and sensors are affected by surface and bulk impurities. In some cases, nanoscale thin films are used as detectors and their life cycle is significantly decreased. In the case of conformal shapes, surfaces with different polishing, decoration and geometries exhibit unusual wetting and nucleation characteristics for impurities and this requires continuous attention for cleaning. The situation for space borne components and vehicles surfaces exposed to wetting liquids requires remote cleaning. In the present paper, we report the effect of surface topographies of substrates with nanoengineered titanium oxide and copper oxide nanoparticles embodied in polystyrene and study the effect of the composites to create different hydrophobic characteristics with great potential for detectors and sensors operating in ultra-violet and infrared regions.

We have observed that inhomogeneity can affect the refringence and emission significantly. We are investigating refractive index and the absorption coefficients of multi-functional sensor materials to understand the defect driven changes using birefringence interferometry. In order to simplify and faster data collection, we are exploring low-cost reflectance probe fiber optics designed in-house. In this presentation we will compare the data obtained by using this new system with available literature data. In this paper we will report results of doped ZnSe crystals grown by physical vapor transport method.

A variety of sensors utilize nanoengineered titanium oxide TiO2 since it changes oxidation states due to high energy exposure. It has been proven to be a good sensor material for radiation sensors. It also provides changes in hydrophobicity on crystalline or glassy surfaces since it affects the contact angles when embodied matrix is treated on the surface. In addition, TiO2 forms very thin film on most substrates and avoids surface corrosion. To increase the sensitivity of sensors one must avoid high contact angle when using materials such as TiO2. In this paper, we propose to discuss the effect of matrix and processing on the interaction by measuring hydrophobic properties of the composites. Accordingly, polystyrene and poly methyl methacrylate filled with TiO2 nanoparticles composites were used. The effect of water, cyclohexane, toluene, and tetrahydrofuron (THF) solvent were studied. It was observed that the mixing of copper oxide significantly alters the sensing capability since it affects the contact angle on the surface and, hence sensitivity.