Francis College of Engineering
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Item Open Access Coupled-wave analysis of apodized volume gratings(Optics Express, 2004-12-27) Tsui, Jing M.; Thompson, Charles; Mehta, V.; Roth, Jeffrey M.; Smirnov, V.I.; Glebov, L.B.Item Open Access Optical phased array power penalty analysis(Optics Express, 2007-04-16) Tsui, Jing M.; Thompson, Charles; Roth, Jeffrey M.Item Open Access Propagation of data-modulated Gaussian beams through holographic optical elements(Optics Express, 2009-03-30) Tsui, Jing M.; Thompson, Charles; Roth, Jeffrey M.Item Open Access Optical pressure/acoustic sensor with precise Fabry-Perot cavity length control using angle polished fiber(Optics Express, 2009-09-14) Wang, Wenhui; Wu, Nan; Tian, Ye; Wang, Xingwei; Niezrecki, Christopher; Chen, JulieItem Open Access Effects of Particle Surface Charge, Species, Concentration, and Dispersion Method on the Thermal Conductivity of Nanofluids(Advances in Mechanical Engineering, 2010) Gowda, Raghu; Sun, Hongwei; Wang, Pengtao; Charmchi, Majid; Gao, Fan; Gu, Zhiyong; Budhlall, BridgetteThe purpose of this experimental study is to evaluate the effects of particle species, surface charge, concentration, preparation technique, and base fluid on thermal transport capability of nanoparticle suspensions (nanofluids). The surface charge was varied by changing the pH value of the fluids. The alumina (Al2O3) and copper oxide (CuO) nanoparticles were dispersed in deionized (DI) water and ethylene glycol (EG), respectively. The nanofluids were prepared using both bath-type and probe sonicator under different power inputs. The experimental results were compared with the available experimental data as well as the predicted values obtained from Maxwell effective medium theory. It was found that ethylene glycol is more suitable for nanofluids applications than DI water in terms of thermal conductivity improvement and stability of nanofluids. Surface charge can effectively improve the dispersion of nanoparticles by reducing the (aggregated) particle size in base fluids. A nanofluid with high surface charge (low pH) has a higher thermal conductivity for a similar particle concentration. The sonication also has a significant impact on thermal conductivity enhancement. All these results suggest that the key to the improvement of thermal conductivity of nanofluids is a uniform and stable dispersion of nanoscale particles in a fluid.Item Open Access Miniature all-silica optical fiber pressure sensor with an ultrathin uniform diaphragm(Optics Express, 2010-04-26) Wang, Wenhui; Wu, Nan; Tian, Ye; Niezrecki, Christopher; Wang, XingweiItem Open Access Low-cost rapid miniature optical pressure sensors for blast wave measurements(Optics Express, 2011-05-23) Wu, Nan; Wang, Wenhui; Tian, Ye; Zou, Xiaotian; Maffeo, Michael; Niezrecki, Christopher; Chen, Julie; Wang, XingweiItem Open Access 3D modeling of dual-gate FinFET(Nanoscale Research Letters, 2012) Mil’shtein, Samson; Devarakonda, L.; Zanchi, B.; Palma, J.The tendency to have better control of the flow of electrons in a channel of field-effect transistors (FETs) did lead to the design of two gates in junction field-effect transistors, field plates in a variety of metal semiconductor field-effect transistors and high electron mobility transistors, and finally a gate wrapping around three sides of a narrow fin-shaped channel in a FinFET. With the enhanced control, performance trends of all FETs are still challenged by carrier mobility dependence on the strengths of the electrical field along the channel. However, in cases when the ratio of FinFET volume to its surface dramatically decreases, one should carefully consider the surface boundary conditions of the device. Moreover, the inherent non-planar nature of a FinFET demands 3D modeling for accurate analysis of the device performance. Using the Silvaco modeling tool with quantization effects, we modeled a physical FinFET described in the work of Hisamoto et al. (IEEE Tran. Elec. Devices 47:12, 2000) in 3D. We compared it with a 2D model of the same device. We demonstrated that 3D modeling produces more accurate results. As 3D modeling results came close to experimental measurements, we made the next step of the study by designing a dual-gate FinFET biased at Vg1 > Vg2. It is shown that the dual-gate FinFET carries higher transconductance than the single-gate device.Item Open Access Fabrication and experimental demonstration of the first 160 Gb/s hybrid silicon-on-insulator integrated all-optical wavelength converter(Optics Express, 2012-02-13) Stamatiadis, Chronis; Stampoulidis, L.; Kalavrouziotis, D.; Lazarou, I.; Vyrsokinos, K.; Zimmermann, L.; Voigt, K.; Preve, G. B.; Moerl, L.; Kreissl, J.; Avramopoulos, H.