This PDF file contains the front matter associated with SPIE Proceedings Volume 7402, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

Development of nanoscale computers that can manipulate molecular information directly is an important issue in nano-engineering. To meet the demand, we are studying on nanoscale automaton based on photonics and DNA technology. This method enables us to achieve information processing using propagating light with a resolution higher than that determined by the diffraction limit. Use of the propagating light offers, in particular, spatially parallel operation of nanoscale automata and utilization of spatial information. As an example of photonic nanoscale automaton, we demonstrated a self-contained DNA nanomachine that is controlled through optical input, although the performance of the operation was not high enough as nanoscale automaton. This photonic DNA nanomachine contains azobenzene-tethered DNA to be controlled through photoisomerization of the azobenzene induced by photonic signal. It is transited to the open-state after ultraviolet light irradiation (cis-form), and to the closed-state after visible-light irradiation (trans-form). In this study, we investigate the operating conditions including the wavelength and bandwidth of irradiation light and the temperature to improve the performance of the DNA nanomachine. Experimental results show that the state of the DNA nanomachine can be changed in less than one minute, which is one-tenth shorter than the previous result, with little decrease in efficiency during ten transition cycles. The transition rate was estimated about hundreds transitions/sec in a volume of 1 cubic micrometer. This suggests that photonic DNA automaton based on the DNA nanomachine can be operated using spatially-parallel photonic signal input.

One dimensional nanostructure such as nanowires is typically fabricated by the wafer-based approach. Here we report nanowires are fabricated by thermal drawing of fiber. A thin viscous semiconductor film internal to the fiber undergoes filamentation driven by a fluid instability while retaining longitudinal structural integrity. Arrays of centimeter-long crystalline nanowires by post-drawing crystallization process are electrically contacted and yield a two-order-of-magnitude change in conductivity between dark and illuminated states. These results hold promise for the nanowire-detector arrays that may be integrated with large-area electronics.

We demonstrate photovoltaic integrated circuits (PVIC) with high-quality large-grain Copper Indium Gallium Selenide (CIGS) obtained with the unique combination of low-cost ink-based or Physical Vapor Deposition (PVD) based nanoengineered precursor thin films and a reactive transfer printing method. Reactive transfer is a two-stage process relying on chemical reaction between two separate precursor films to form CIGS, one deposited on the substrate and the other on a printing plate in the first stage. In the second stage, these precursors are brought into intimate contact and rapidly reacted under pressure in the presence of an electrostatic field while heat is applied. The use of two independent thin films provides the benefits of independent composition and flexible deposition technique optimization, and eliminates pre-reaction prior to the synthesis of CIGS. High quality CIGS with large grains on the order of several microns, and of preferred crystallographic orientation, are formed in just several minutes based on compositional and structural analysis by XRF, SIMS, SEM and XRD. Cell efficiencies of 14% and module efficiencies of 12% have been achieved using this method. When atmospheric pressure deposition of inks is utilized for the precursor films, the approach additionally provides further reduced capital equipment cost, lower thermal budget, and higher throughput.

Monodispersed CdS nanoparticles (NP) are dip coated on porous ZnO thin film deposited by inkjet printing. Optical absorption characteristics of the composite films show that the composite exhibits two main peaks centered at 355 nm due to the absorption at UV region from ZnO, and 433 nm arising from CdS NP. On UV radiations the electrical conductivity of CdS/ZnO composite thin film with 5 dip cycles is found to be enhanced more than three orders magnitude compared with that of the ZnO which we attribute to be the effect of interfacial charge transfer. Also, the UV photoresponse of ZnO shows pronounced enhancement after CdS capping.

Real-time optical imaging and tracking of particles in a complex environment to understand coordinated events has attracted researchers from various areas such as biomechanics. Here, we report a way for real time detection and tracking of micron size particles in time-space-wavelength mapping technology by using a single detector. Experimentally, we demonstrate real time tracking of micron size glass particles with 50ns temporal resolution and <3μm spatial resolution. Submicron resolution and faster temporal resolution are achievable with further optimization. The proposed technique utilizes the timewavelength technology, which has been proven to be very effective in real time digitization of ultra fast RF signals, and arbitrary waveform generation by random objects. In this work we use a broad band continuum source generated by a 20MHz fiber laser to emit 50nm short pulses at 1550nm. Following a dispersive time wavelength mapping in a chirped fiber grating and space-time-wavelength mapping through a diffraction grating with 600lines/mm, we generate an elliptical beam where each wavelength component corresponds to different time and position in space. Then the generated beam is focused on an image plane by using 20X-40X microscope objectives. The presence of particles on the image plane induces amplitude modulation on each pulse which is captured in real time by a high speed digitizing oscilloscope with 20GS/s sampling rate. The trajectory of the particle is extracted from the dynamic amplitude modulation in a post processing. The same system has also been utilized for imaging of particles by using one dimensional scanning.

We quantify the influence of thermopiezoelectric effects in nano-sized Al_xGa_1-xN/GaN heterostructures for pressure sensor applications based on the barrier height modulation principle. We use a fully coupled thermoelectromechanical formulation, consisting of balance equations for heat transfer, electrostatics and mechanical field. To estimate the vertical transport current in the heterostructures, we have developed a multi-physics model incorporating thermionic emission, thermionic field emission, and tunneling as the current transport mechanisms. A wide range of thermal (0-300 K) and pressure (0-10 GPa) loadings has been considered. The results for the thermopiezoelectric modulation of the barrier height in these heterostructures have been obtained and optimized. The calculated current shows a linear decrease with increasing pressure. The linearity in pressure response suggests that Al_xGa_1-xN/GaN heterostructure-based devices are promising candidates for pressure sensor applications under severe environmental conditions.

Here, we emphasize the importance of a bottom reflector for achieving unidirectional far-field emission. As a result, over 80% of photons generated inside the cavity can be collected within a divergence angle of ±30° from the top. We also discuss interesting analogy in which the nanocavity-bottom reflector coupled system is treated as a point-like emitter in front of a mirror. Based on such a view point, the observed directivity is explained by using a comprehensive interference model. Finally, we propose a very practical form of an efficient photonic crystal nanolaser bonded on a flat metal surface, which may enable current injection and room-temperature continuous-wave operation.

The future of mixed-signal, memory, and microprocessor technologies are dependent on ever increasing analog and digital integration and higher cell densities. However, device variability creates challenges at each new technology node which decreases yield, performance, and noise margins. At these device dimensions the low-frequency noise is dominated by the influence of one or more traps capturing and emitting charge in the oxide creating wide variations in noise from otherwise identical devices. Existing processes of record have been extended well beyond the ranges previously deemed feasible or reliable and single electron events and random telegraph noise signals become important.

InSb nanowire field effect transistors (NWFET) were fabricated using electrochemically synthesized nanowires. To accurately extract transistor parameters, we introduced a model which takes into account the often ignored ungated nanowire segments. A significant improvement in extracted device parameters was observed which demonstrated that conventional models tend to underestimate the gate effect and therefore lead to lower carrier mobilities. Based on the model, we obtained a NWFET ON current of 11.8uA, an I_ON/I_OFF ratio of 63.5 and hole mobility of 292.84 cm²V^-1s^-1.

Dye doped polymer photonic crystal band edge lasers are applied for evanescent wave sensing of cells. The lasers are rectangular shaped slab waveguides of dye doped polymer on a glass substrate, where a photonic crystal is formed by 100 nm deep air-holes in the surface of the 375 nm high waveguides. The lasers are fabricated by combined nanoimprint and photolithography (CNP) in Ormocore hybrid polymer doped with the laser dye Pyrromethene 597. The lasers emit in the chip plane at a wavelength around 595 nm when pumped with 5 ns pulses from a compact frequency doubled Nd:YAG laser. We investigate the sensitivity of photonic crystal band-edge lasers to partial coverage with HeLa cells. The lasers are chemically activated with a flexible UV activated anthraquinone based linker molecule, which enables selective binding of cells and molecules. When measuring in Phosphate Buffered Saline (PBS), which has a refractive index close to that of the cells, the emission wavelength depends linearly on the cell density on the sensor surface. Our results demonstrate that nanostructured hybrid polymer lasers, which are cheap to fabricate and very simple to operate, can be selectively chemically activated with UV sensitive photolinkers for further bioanalytical applications. This opens the possibility to functionalize arrays of optofluidic laser sensors with different bio-recognition molecules for multiplexed sensing. The linear relationship between cell coverage and wavelength indicates that the slight refractive index perturbation from the partial coverage of the sensor influences the entire optical mode, rather than breaking down the photonic crystal feedback.

Product engineering of micro and nano technology (MNT) devices differs substantially from product engineering in more traditional industries. The general development approach is mostly bottom up, as it centers around the available fabrication techniques and is characterised by application specific fabrication flows, i.e. fabrication processes depending on the later product. In the first part of this paper we introduce a comprehensive customer-oriented product engineering methodology for MNT products that regards the customer as the driving force behind new product developments. The MNT product engineering process is analyzed with regard to application-specific procedures and interfaces. An environment for the development of MNT manufacturing processes has been identified as a technical foundation for the methodology and will be described in the second part of this paper.

In this study we present a simulation model to optimize and engineer PbSe/Pb _0.934 Sr_0.066 Se quantum well laser structures which is a promising material system that has been used in IR Tunable Laser Spectroscopy. Four nanostructures were investigated: Single Quantum Well Lasers (SQW), Separate Confinement Heterostructure_Single Quantum Well Lasers (SCH_SQW), Multiple Quantum Well Lasers (MQW), and Modified Multiple Quantum Well Lasers (MMQW). We calculated the emitted wavelengths, the amount of optical energy that was confined in these structures, modal gain, total losses and the threshold current behavior as a function of laser cavity length and mirror reflectivity. The results showed that at low modal gain values, there are crossover points between the gain-current density curves for the four structures investigated. These points are crucial for determining the structure of choice with optimize and design parameters. The anisotropy in the constant energy surfaces and effects of non parabolic band structure for this system are included in the calculations. Finally, the theoretical model used in this research can be used with other material systems as a design and optimization tool for quantum well laser structures.

We report on the room temperature photoluminescence (PL) at 1.54 μm from erbium-doped silicon rich silicon oxide (ErSRSO) films, fabricated on fused quartz by thermal evaporation followed by thermal-annealing in air. PL measurements show maximum intensity in samples annealed at 1000°C for four hours. X-ray diffraction (XRD) structural analyses show that annealing caused the formation of active Er³⁺ (Er₂O₃) centers. XRD and PL results show that increasing Er₂O₃ concentration does not necessarily lead to an increase in photoluminescence. Compositional analysis using Time-of-Flight Secondary Ion Mass Spectroscopy (TOF-SIMS) depth-profiling shows a strong correlation between the presence of contiguous Si rich regions and Er₂O₃ centers on the one hand and the observed PL on the other. The combination of PL, XRD, and TOF-SIMS results indicate the presence of silicon nanoclusters and its sensitization of erbium.

Structures of nanometric scale are increasingly present in optical systems. Unfortunately, effects in the intermediate fiel of a sequence of circular apertures are little known. We investigated the effects of such structures on monochromatic and pulsed beams, and our numerical simulations predict results that could be disastrous to optical systems. For continuous waves, we calculated high intensities that could damage materials or change their index of refraction. For pulsed beams, strong pulse-shaping effects are predicted. Caution should therefore be used when designing systems containing circular apertures; diffraction effects in the near fiel should be considered.

Formation and characteristic comparing of Aluminium titanate (AT) was achieved through solid-state and sol-gel processes. In the sol-gel process controlling of the nano-sized particles was followed by addition of a polymeric coherent agent in the transparent sol. In the present work 2wt% Magnesia and 4wt% zirconium mullite were added as the additives to the samples for sintering acceleration of Aluminium Titanate and also AT properties were optimized at low temperature. XRD analysis was confirmed the formation of about 90% nano-sized AT at 1400°C without addition of MgO in the sol-gel process. The influence of Mg and Zr addition and heat treatment of the precursors were studied on phase formation and microstructure development in Aluminum Titanate in both procedures. Studies of calcined powders containing additives at 1300-1350°C show the significant increasing of AT formation and the sintering was done very optimally as well. The Formation of AT phase, sintering characteristics and microstructure features were reported.

Focused Ion Beam (FIB) was employed to fabricate nanoimprint stamps. Complex three dimensional (3D) micro-nano patterns were fabricated including the emblems of Beijing 2008 Olympic Games and Shanghai 2010 World Expo on a single stamp. These micro/nano structures were then faithfully replicated to SU-8 2000.1 resist, with low imprint temperature. Field emission-scanning electron microscope (FE-SEM) and atomic force microscopy (AFM) were used to characterize both stamp and replica's surface profile and replication fidelity. The results show that nanoimprint with the FIB fabricated stamps can successfully replicate complex 3D micro-nano SU-8 structures at the same time under low temperature.

We report on the diffraction properties of a volume hologram recorded at a wavelength of 404 nm in a ZrO₂ nanoparticle-polymer compsite film. It is found that the refractive index modulation and the material recording sensitivity are as high as 8 × 10^-3 and 9000 cm/J, respectively, at the ZrO₂ nanoparticle concentration of 35 vol.% and a recording intensity of 5 mW/cm². These values are comparable to or higher than those recorded at a wavelength of 532 nm. Effects of the ZrO₂ nanoparticle dispersion in acrylate monomer on the polymerization kinetics are also examined by using a photo-differential scanning calorimeter. It is found that the incorporation of ZrO₂ nanoparticles increases the polymerization rate.

The simple and inexpensive technique of electrospinning was used for the production of long GaN nanofibers. The fibers were made using a precursor solution composed of pure Gallium Nitrate dissolved in dimethylacetamide (DMA) and a viscous solution of Cellulose acetate dissolved in a mixture of DMA and acetone. Using a tube furnace, they were sintered under a Nitrogen atmosphere to decompose the polymer and to reduce Oxygen contamination. This process was followed by sintering under a NH₃ flow to complete the synthesis of wurtzite GaN. XRD, ESEM, and FTIR analysis were used to verify the chemical and structural composition of the samples. The I-V characteristics of a device constructed using a single GaN nanofiber showed the formation of ohmic contacts.

Nanophotonics and photonic crystals (PhCs) are emerging as platforms with which highly sensitive biosensor devices can be fabricated. One such device under development by our group is a nano-opto-fluidic fluorescence emission enhancement biosensor that can provide significant increase in photon emission and associated detection limit. The inclusion of tunability of thin film PhCs patterns offers means of adjusting fabrication errors and provides a mechanism for increased device functionality. Therefore, this work aims to provide active tunability of the bandgap of PhC patterns in piezoelectric AlN thin films through piezoelectric deformation. Modeling efforts of bandgap tuning of 'as-drawn' and deformed 1- and 2-D PhC lattice structures, using coupled results from PhC optical behavioral modeling tools such as: MIT Photonic Bands (MPB) and finite element modeling using ANSYS, are discussed. Furthermore, the fabrication process of 1D photonic crystals in AlN will be presented.