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We demonstrate intra- and inter-board level optical interconnects using polymer waveguides and waveguide couplers consisting of both 45 degree total internal reflection (TIR) mirrors and inkjet-printed micro-lenses. Surface normal couplers consisting of 50 µm × 50 µm waveguides with embedded 45 degree mirrors are fabricated using a nickel mold imprint. Micro-lenses, 70 µm in diameter, are inkjet-printed on top of the mirrors. We characterize the optical transmission between waveguides located on different boards in terms of insertion loss, mirror coupling loss, and free space propagation loss as a function of interconnection distance in free space. Each mirror contributes 1.88 dB loss to the system, corresponding to 65% efficiency. The printed micro-lenses improve the transmission by 2-4 dB (per coupler). Data transmission at 10 Gbps reveals that inter-board interconnects has a bit error rate (BER) of 1.1 × 10(-10) and 6.2 × 10(-13) without and with the micro-lenses, respectively.

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We demonstrated a practical process of fabricating nickel molds for nanoimprinting. Dual-side polished glass is chosen as the substrate on which nickel nanostructures are successfully electroplated. Photonic crystal structures with 242 nm diameters and other nanoscale pillars down to 9 nm diameters are achieved over a large area. The electroplating parameters are investigated and optimized. This process extends the feasibility of electroplating process to nanoscale and shows great potential in nanoimprint mold fabrication with its low cost, straightforward process and controllable pattern structures.

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In this paper, an innovative 3-to-3 bi-directional optical bus architecture based on multimode polymer waveguides with embedded 45° micro-mirrors was successfully demonstrated. With a lithography-free imprinting process by high quality electroplated metallic mold, the device can be precisely replicated with a low fabrication cost. Superior to any point-to-point optical waveguide, the implemented optical bus structure is capable of broadcasting and receiving high speed data at 10 Gbit/sec among multiple points as a high performance optical backplane.

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In this paper, we report the theoretical study of polymer-based photonic crystals for laser beam steering which is based on the superprism effect as well as the experiment fabrication of the two dimensional photonic crystals for the laser beam steering. Superprism effect, the principle for beam steering, was separately studied in details through EFC (Equifrequency Contour) analysis. Polymer based photonic crystals were fabricated through double exposure holographic interference method using SU8-2007. The experiment results showed a beam steering angle of 10 degree for 30 nm wavelength variation.

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In this paper, we presented fabrication of nickel based metal mold with 45 degrees tilted surfaces on both ends of the channel waveguide through electroplating process. To obtain a precise 45 degrees tilted angle, a 50microm thick SU-8 layer was UV exposed under de-ionized water, with repeatable error control of 0.5 degrees . The polymeric waveguide array with 45 degrees micro-mirrors, which is formed by a UV imprinting method with the fabricated metallic mold, shows total insertion losses around 4dB, propagation loss around 0.18dB/cm and 75% coupling efficiency.

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The adsorption behavior of human fibrinogen (Hfg) on single-walled carbon nanotube (SWNT) films was investigated using scanning electron microscopy (SEM) and near edge X-ray absorption fine structure (NEXAFS) spectroscopy. It was shown in the SEM images that fibrinogen was adsorbed strongly on the surface of SWNT when the samples were incubated in the Hfg solutions for 10 min. The dependence of adsorption on the concentration of fibrinogen was also investigated and it was found that adsorption increased with increasing concentration. In order to further explore the adsorption of fibrinogen on SWNT surface, NEXAFS spectra were obtained at the N K-edge and the C K-edge. The results confirmed the conclusion regarding the dependence of adsorption on fibrinogen concentration. It is demonstrated that, due to its high sensitivity to the surface elements, NEXAFS spectroscopy is a powerful tool to investigate the adsorption of fibrinogen on SWNT films.

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Resonant Raman scattering (RRS) spectra of individual carbon nanotubes on a SiO2 substrate have been investigated first in the temperature range of 100-600 K (Phys. Rev. B 2002, 66, 115411). It was revealed by the intensity abnormality of the radial breathing mode (RBM) that the carbon nanotubes have a temperature-dependent density of electronic states. This means that the previously reported temperature coefficients of RBM of carbon nanotubes are smaller than their "real" ones for the bulk samples of single- or double-walled carbon nanotubes. Comparatively, the G line of individual nanotubes shows no observable difference relative to the bulk samples.

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Large quantities of indium nitride (InN) nanowires are synthesized by the in situ nitriding of indium oxide (In(2)O(3)) powders in an ammonia (NH(3)) flux. Tens of milligrams of nanowires are obtained in one batch. Every 100 mg of In(2)O(3) starting powder can produce up to 65 mg of InN nanowires under the optimized conditions. The synthesized nanowires grow along the [001] direction with excellent crystallinity. They are of high purity and are 30-50 microm in length with an almost uniform diameter of about 100 nm. Photoluminescence measurements of the nanowires exhibit a strong peak at 707 nm. An optical bandgap of about 1.7 eV is estimated based on the absorption spectrum. The experimental results also demonstrate that the approach of nitriding In(2)O(3) powders in situ is feasible for the synthesis of high-purity InN nanowires in large quantities, with good reproducibility and without catalyst materials. The synthesis of InN nanowires in large quantities would be of benefit to the further study and understanding of their intrinsic properties, as well as being advantageous for their potential application in nanodevices.

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At a low temperature of 450 degrees C, ZnS nanoribbons have been synthesized on Si and KCl substrates by a simple chemical vapor deposition (CVD) method with a two-temperature-zone furnace. Zinc and sulfur powders are used as sources in the different temperature zones. X-ray diffraction (XRD), selected area electron diffraction (SEAD), and transmission electron microscopy (TEM) analysis show that the ZnS nanoribbons are the wurtzite structure, and there are two types-single-crystal and bicrystal nanoribbons. Photoluminescence (PL) spectrum shows that the spectrum mainly includes two parts: a purple emission band centering at about 390 nm and a blue emission band centering at about 445 nm with a weak green shoulder around 510 nm.