The target of this work is to optically interconnect a semiconductor laser and a single mode fiber (SMF) through a simple Si bench technology using buried waveguide devices. This technology is suitable for applications such as optical transceivers and add-and-drop multiplexers. Three major components, namely, planarized laser diode, buried waveguide, and SMF are hybrid integrated on the Si bench. The ridge-type laser was planarized by BCB etch-back process, and was flip-chip mounted on the Si bench. On the other hand, the sol-gel buried waveguide was passively aligned to SMF using V-groove and U-groove techniques. Miss-alignment loss as low as 1 dB can be obtained.

The objective of this thesis is to integrate the optical waveguide and single mode fiber in a passive alignment way on a silicon bench. This technique can reduce the complexity of packaging the individual components and increase yield of the module in order to achieve the goal of the mass production. In this module, buried waveguide structure was used for light guidance. A 1.31µm semiconductor laser was used as the input light source. Light signal launched by semiconductor laser is transferred through the buried waveguide into the single mode fiber. This module structure is consisted of two major parts, namely, the buried waveguide and the silicon bench. Buried optical Waveguide uses SO2 as the bottom cladding. Conventional photolithography procedures and etching technique were used to form a trench on the SiO2 cladding. The waveguide core was fabricated by coating the organic-inorganic hybrid materials into the trench. Finally, an organic-inorganic hybrid materials with a refractive index smaller than that of the core is used as the top cladding. The silicon benches were obtained by etching V-groove and saw-cutting U-groove on the silicon substrates for fixing the fiber. The patterning of buried waveguide and silicon V-groove were fabricated by a single optical mask procedure. Therefore accurate alignment between the waveguide and the single mode fiber can be obtained.

1 x N optical power splitters using hybrid sol-gel glasses based on buried waveguide structure on silicon substrate were fabricated. The advantage over conventional ridge structures is the fact that Y branch of the splitters can be easily obtained with the buried structure using standard photo lithography processes. Now we can successfully make the width of Y branch of less of 1um. Proximity printing was used to define the waveguide trench on sol-gel films. Then burying the sol-gel glass into the trench to define waveguide core. Finally the waveguide was packaged for measurement after coating a sol-gel top cladding layer onto the guiding layer. The propagation losses of this waveguide device are 0.69 dB/cm and 0.70 dB/cm for TE and TM polarized lights. The coupling losses are 1.57 dB and 1.89 dB for TE and TM lights with a index contrast of 0.66 %. The insertion loss and the branching loss of the 1¡Ñ2 splitter are 5.7 dB and 0.3 dB¡Arespectively.

This thesis presents a novel monolithic phased array implemented using the RF MEMS technology. The structure, which is designed at 15 GHz, consists of four linearly placed microstrip patch antennas, 3-bit distributed RF MEMS low-loss phase shifters, and a corporate feed network. The RF MEMS phase shifter employed in the system consists of three sections with a total of 28 unit cells, and it occupies an area of 22.4 mm &amp / #61620 / 2.1 mm. The performance of the phase shifters is improved using high-Q metal-air-metal capacitors in addition to MEMS switches as loading elements on a high-impedance coplanar waveguide transmission line. The phased array is fabricated monolithically using an in-house surface micromachining process, where a 1.2-&amp / #61549 / m thick gold structural layer is placed on a 500-&micro / m thick glass substrate with a capacitive gap of 2 &amp / #61549 / m. The fabrication process is simple, requires only 6 masks, and allows the implementation of various RF MEMS components on the same substrate, such as RF MEMS switches and phase shifters. The fabricated monolithic phased array occupies an area of only 6 cm &amp / #61620 / 5 cm. The measurement results show that the phase shifter can provide nearly 20&amp / #61616 / /50&amp / #61616 / /95&amp / #61616 / phase shifts and their eight combinations at the expense of 1.5 dB average insertion loss at 15 GHz. The phase shifters can be actuated with 16 V, while dissipating negligible power due to its capacitive operation. It is also shown by measurements that the main beam can be steered to 4&amp / #61616 / and 14&amp / #61616 / by suitable settings of the RF MEMS phase shifters.

In the traditional analysis of acoustic wave propagation in an ocean waveguide, it's generally assumed that acoustic properties, including density and sound speed profile at seabed are taken to be constant. However, recent experimental data provided by Hamilton~(1980)~ have shown that the sediment layer in the seabed experiences a transitional change in which the density and the sound speed vary continuously from one value at the top to another at the bottom of the layer. The objective of this study is to investigate the surface-generated ambient noise in an isovelocity waveguide with a non-homogeneous fluid sediment layer. The noise model was first proposed by Kuperman and Ingenito~(1980) in the study of surface-generated ambient noise using normal mode approach, and the model proposed by Robins (1993) in the study of the sediment layer change in which the density and the sound speed vary continuously. It is demonstrated that the noise intensity may be affected by the stratification mainly through the continuous spectrum, in that the continuous spectrum is equally important as the normal modes in the present analysis. The continuous variation of the sediment layer reduces the contrast of the interface, which in turn affects the wavenumber spectrum, particularly in the continuous spectrum region. The results show that the horizontal correlation length of the noise field increases as that of the noise random sourse increase, but the vertical correlation length of the noise field decreases as that of the noise random sourse increase.

<p>In this thesis various subjects at the crossroads of quantummechanics and device physics are treated, spanning from afundamental study on quantum measurements to fabricationtechniques of controlling gates for nanoelectroniccomponents.</p><p>Electron waveguide components, i.e. electronic componentswith a size such that the wave nature of the electron dominatesthe device characteristics, are treated both experimentally andtheoretically. On the experimental side, evidence of partialballistic transport at room-temperature has been found anddevices controlled by in-plane Pt/GaAs gates have beenfabricated exhibiting an order of magnitude improvedgate-efficiency as compared to an earlier gate-technology. Onthe theoretical side, a novel numerical method forself-consistent simulations of electron waveguide devices hasbeen developed. The method is unique as it incorporates anenergy resolved charge density calculation allowing for e.g.calculations of electron waveguide devices to which a finitebias is applied. The method has then been used in discussionson the influence of space-charge on gate-control of electronwaveguide Y-branch switches.</p><p>Electron waveguides were also used in a proposal for a novelscheme of carrierinjection in low-dimensional semiconductorlasers, a scheme which altogether by- passes the problem ofslow carrier relaxation in suchstructures. By studying aquantum mechanical two-level system serving as a model forelectroabsorption modulators, the ultimate limits of possiblemodulation rates of such modulators have been assessed andfound to largely be determined by the adiabatic response of thesystem. The possibility of using a microwave field to controlRabi oscillations in two-level systems such that a large numberof states can be engineered has also been explored.</p><p>A more fundamental study on quantum mechanical measurementshas been done, in which the transition from a classical to aquantum "interaction free" measurement was studied, making aconnection with quantum non-demolition measurements.</p>

Polymeric waveguide-on-flex has the potential to replace complex and costly light-turning devices in optoelectronic applications. As light signals are propagated and confined through the definition of core-cladding interface, the light guiding structure is required to adhere well and ensure long term interfacial stability. This thesis addresses the gap that has emerged in the fundamental material issues such as the polymeric optical waveguide materials deposited on the flexible substrates. In addition, this thesis investigates the feasibility of a new approach using electrostatic-induced lithography in micro-patterning of polymer, in optical waveguide fabrication. Plasma treatment is applied to enhance interfacial adhesion between flex substrates and optical cladding layers. The modified flex surfaces of polyimide KaptonHNTM and liquid crystal polymer VecstarTM materials are characterised. In addition, sonochemical surface treatment is evaluated on these flexible substrates. ToF-SIMS depth profiling has confirmed the interface reaction mechanisms where it has shown that plasma treatment increases the interfacial interpenetration. The larger interfacial width increases the possible entanglement mechanism between the polymer chains. These results, together with the double cantilever beam testing, indicate the strengthening of the polymeric interface upon plasma treatment, which is essential for long term optical and mechanical stability of waveguide-on-flex applications. A new method of micro-pattering of polymer material has been adopted for fabricating multimode waveguide-on-flex. The method, using an electrostatic-induced lithography, is developed to produce 50 μm x 50 μm arrays of polysiloxane LightlinkTM waveguide on flex. This thesis looks at various process recipes of the technique and reports the pattern formation of polymeric optical core. By adjusting the spin-coated liquid core thickness, pre-bake condition, UV exposure and applied voltage, the aspect ratio and profile of the optical core microstructure can be varied. As the electrostatic pressure overcoming the surface tension of spin-coated waveguide material induces the optical core formation, the core structure is smooth, making it ideal for low scattering loss waveguide. The propagation loss of fabricated waveguide is measured at 1.97 dB/cm at 850 nm wavelength. The result shows that the use of electrostatic-induced lithography in optical polymer is a promising approach for low cost and low temperature (<150 °C) processing at back end optical-electrical integrated circuitry assembly.

We have demonstrated a flexible optical waveguide film with integrated VCSEL and PIN photodiode arrays for the fully embedded board level optical interconnection system. One of the most critical issues in the fully embedded board level optical interconnection system is the signal beam coupling between the guided-wave structure and the aperture of VCSEL (or PIN photodiode). The coupling efficiencies of spherical mirrors are calculated as a function of mirror radius. The optimum mirror radius ranges which are compatible with the fully embedded board level optical interconnection system are theoretically verified. The thermal characteristics of a thin film VCSEL are studied both theoretically and experimentally. The thermal resistances of VCSEL with variable thickness, ranging from 10 [mu]m to 200 [mu]m, have been determined by measuring the output wavelength shift as a function of the dissipated power. The thermal simulation results agree reasonably well with experimentally measured data. From the thermal management point of view, a thinned VCSEL has an exclusive advantage due to the reduction of the thermal resistance. The thermal resistance of 10 [mu]m thick VCSEL is 40 % lower than that of 200 [mu]m thick VCSEL. The theoretical analysis of thermal via effects is performed to determine optimized thickness ranges of thin film VCSEL for the fully embedded structure. Thermal resistance of the fully embedded thin film VCSEL with closed and open thermal via structures are also evaluated with the suitable VCSEL thickness reported. The high-performance computing system is demonstrated using a 16-channel optical backplane using thin film volume holographic gratings. The optical backplane contains TO-46-Can-packaged VCSELs and photodiodes as an optical transmitter and receiver, respectively. Optical packaging plates are fabricated for 4 X 8 array packaging for 16-VCSELs and 16-Photodiodes. Packaging issues including crosstalk and alignment tolerance are studied to design a low cost optical packaging scheme. Thin film volume hologram grating is fabricated on glass substrate to redirect light beams. An individual single channel performs at a 100 MHz data transfer rate. The high-performance computing system using 16-channel optical backplane is demonstrated at a 1.6 Gbps data transmission. / text

Surface acoustic wave sensors have been a focus of active research for many years. Its ability to respond for surface perturbation is a basic principle for its sensing capability. Sensitivity to surface perturbation changes with every inter-digital transducer (IDT) design parameters, substrate selection, metallization choice and technique, delay line length and working environment. In this thesis, surface acoustic wave (SAW) sensors are designed and characterized to improve sensitivity and reduce loss. To quantify the improvements with a specific design configuration, the sensors are employed to measure temperature. Four SAW sensors design configurations, namely bi-directional, split electrode, single phase unidirectional transducer (SPUDT) and metal grating on delay line (shear transvers wave sensors) are designed and then fabricated in Nanotechnology Research and Education Center (NREC) facility using traditional MEMS fabrication processes Additionally, sensors are then coated with guiding layer SU8-2035 of 40 m using spin coating and SiO2 of 6 m using plasma enhanced chemical vapor deposition (PECVD) process. Sensors are later diced and tested for every 5oC increment using network analyzer for temperature ranging from 30oC–0.5oC to 80oC–0.5oC. Data acquired from network analyzer is analyzed using plot of logarithmic magnitude, phase and frequency shift. Furthermore, to investigate the effect of metallization technique on the sensor performance, sensors are also fabricated on substrates that were metallized at a commercial MEMS foundry. All in-house and outside sputtered sensor configurations are compared to investigate quality of sputtered metal on wafer. One with better quality sputtered metal is chosen for further study. Later sensors coated with SU8 and SiO2 as guiding layer are compared to investigate effect of each waveguide on sensors and determine which waveguide offers better performance. The results showed that company sputtered sensors have higher sensitivity compared to in-house sputtered wafers. Furthermore after comparing SU8 and SiO2 coated sensors in the same instrumental and environmental condition, it was observed that SU8 coated di-directional and single phase unidirectional transducer (SPUDT) sensors showed best response.

Thrombospondin-1 (TSP-1) binding to its membrane receptor CD47 results in an inhibtion of the nitric oxide (NO) receptor soluble guanylate cyclase (sGC) and a decrease in intracellular cGMP levels. This causes physiologic effects such as vasoconstriction and a rise in blood pressure. The mechanism by which TSP-1 binds to CD47 at the membrane to decrease sGC activity is largely unknown. CD47 can physically associate with a number of binding partners, including α(v)β₃ and vascular endothelial growth factor receptor 2 (VEGFR2). Binding of a C-terminal fragment of TSP-1 called E3CaG1 to CD47 leads to a rise in intracellular calcium ([Ca²⁺](i)), which decreases sGC activity via a phosphorylation event. Binding of E3CaG1 is also known to disrupt the interaction between CD47 and VEGFR2, leading to a decrease in endothelial nitric-oxide synthase (eNOS) activity and cGMP levels through an Akt signaling pathway. However, it is not known whether other membrane proteins associated with CD47 are required for E3CaG1 binding and a subsequent [Ca²⁺](i) increase. Plasmon-waveguide resonance (PWR) spectroscopy was employed to elucidate the mechanism of TSP-1 inhibition of sGC activity through membrane complexes involving CD47. Using PWR, I found E3CaG1 can bind specifically to CD47 within native Jurkat membranes with picomolar and nanomolar dissociation constants (K(d)), suggesting multiple CD47 complexes are present. Among these complexes, CD47/VEGFR2 was found to bind E3CaG1 with a picomolar K(d)and CD47/α(v)β₃ was found to bind E3CaG1 with a nanomolar K(d). In addition, the presence of an anti-VEGFR2 antibody inhibited the E3CaG1-induced calcium response, which suggested CD47 in complex with VEGFR2 was responsible for TSP-1 reduction of sGC activity. I show that when both CD47 and VEGFR2 are returned to a HEK 293T cell line that does not contain these receptors, an increase in [Ca²⁺](i) upon E3CaG1 binding is restored. Interestingly, E3CaG1 was also found to bind to VEGFR2 in complex with the integrin α(v)β₃ on CD47-null cell lines and their derivations, causing a decrease in [Ca²⁺](i) levels. Therefore, the third type 2 repeat and C-terminal domains of TSP-1 can cause both increases and decreases in calcium based upon the availability of protein complexes to which it binds.