A novel current-sensing circuit that can operate from 1MHz to 4MHz has been designed and implemented for high-frequency low-power dc-dc power converter applications. The design is based on SenseFET concept with embedded SenseFETs in the main switch (MS) and synchronous rectifier (SR). An intermediate RC filter merges outputs from the MS and SR SenseFETs and supplies a smooth voltage signal to an op-amp. This reduces the need for a very high gain-bandwidth op-amp circuit and improves the efficiency of the power converter. The circuit has configurable feedback gain in order to increase current sensing accuracy when the average inductor current is small.

Many wireline communication systems are moving toward a digital based architecture for the receiver that requires a front-end high-speed ADC. This thesis proposes a two-level time-interleaving topology for realizing such an ADC, comprising front-end time-interleaved sub-rate track-and-holds each followed by a sub-ADC which is further time-interleaved to a slower clock frequency. The design, implementation and measurement of the 1.25GS/s sub-ADC fabricated in 65nm CMOS technology is presented. The SAR architecture is chosen for its low power and digital friendly nature along with an unconventional C-2C capacitive DAC implementation for higher bandwidth. The time-interleaved C-2C SAR ADC runs with a 1.0V supply, and it has a full input range of 1.0V\subscript{pp} differential, while consuming 34mW. The SNDR is 39.4dB at low frequency and the FOM is 360fJ/conv-step and 428fJ/conv-step at low and Nyquist input frequencies respectively. The SNDR is 34dB at 4GHz input frequency, which is more than 6 times the Nyquist frequency.

Many wireline communication systems are moving toward a digital based architecture for the receiver that requires a front-end high-speed ADC. This thesis proposes a two-level time-interleaving topology for realizing such an ADC, comprising front-end time-interleaved sub-rate track-and-holds each followed by a sub-ADC which is further time-interleaved to a slower clock frequency. The design, implementation and measurement of the 1.25GS/s sub-ADC fabricated in 65nm CMOS technology is presented. The SAR architecture is chosen for its low power and digital friendly nature along with an unconventional C-2C capacitive DAC implementation for higher bandwidth. The time-interleaved C-2C SAR ADC runs with a 1.0V supply, and it has a full input range of 1.0V\subscript{pp} differential, while consuming 34mW. The SNDR is 39.4dB at low frequency and the FOM is 360fJ/conv-step and 428fJ/conv-step at low and Nyquist input frequencies respectively. The SNDR is 34dB at 4GHz input frequency, which is more than 6 times the Nyquist frequency.

Preliminary investigations were carried out in order to explore the potential of laser-stimulated capillary growth in a blood vessel-on-a-chip. To fulfill the project objective, a series of experiments in both directions of two photon fluorescence imaging and laser-semitransparent materials interaction were performed. A purpose-built two-photon fluorescence imaging resolution was tested by imaging 1 micron diameter fluorescent beads. Also, the potential of fluorescence imaging in the waveguide writing eld as well as the biological eld was studied. Further, for laser ablation on the mouse artery loaded in the microfluidic channel, the processing window was found such that the damage induced by femtosecond laser just a effects the artery, not the other interfaces of the microfluidic chip. At the end, the result of laser trepanning on the mouse artery wall combined with two photon fluorescence imaging was shown. These results will be useful for more advanced biological study such as angiogenesis.

Resource management –particularly power and spectrum management– is becoming increasingly important owing to the fast growing market of smart-phones and other power-hungry wireless devices. While WiFi and cellular communication accounts for a significant portion of the smart-phone power expenditure, spectrum is equally paramount and scarce as well. This demands for an efficient and judicious resource management schemes that is also viable in terms of the practical implementation and complexity. This thesis focuses on the various setups of multi-channel relaying system as an emerging wireless technology, and provides rate optimal, yet easy-to-implement, resource management solutions for them. We exploit the channel pairing (CP) capability of a multi-channel relay node in our design. This capability allows the relay to receive a signal from one channel and transmit a processed version of the signal on a different channel. CP jointly optimized with power allocation (PA), which determines each channel’s power, can lead to significant improvement in spectral efficiency. For two setups, namely multi-hop and multi-user setups, we present the total achievable rates through optimizing CP, PA and channel-user assignment which incurs multi-user diversity. While the achievable rates provide theoretical insight for the performance of such systems, we next incorporate the integer nature of bit loading and rate adaptation, and via an innovative optimization technique, we present the jointly optimal solution to the problem of bit loading, PA and CP.

Preliminary investigations were carried out in order to explore the potential of laser-stimulated capillary growth in a blood vessel-on-a-chip. To fulfill the project objective, a series of experiments in both directions of two photon fluorescence imaging and laser-semitransparent materials interaction were performed. A purpose-built two-photon fluorescence imaging resolution was tested by imaging 1 micron diameter fluorescent beads. Also, the potential of fluorescence imaging in the waveguide writing eld as well as the biological eld was studied. Further, for laser ablation on the mouse artery loaded in the microfluidic channel, the processing window was found such that the damage induced by femtosecond laser just a effects the artery, not the other interfaces of the microfluidic chip. At the end, the result of laser trepanning on the mouse artery wall combined with two photon fluorescence imaging was shown. These results will be useful for more advanced biological study such as angiogenesis.

Nanocrystal solids represent an exciting new class of materials. These are often referred to as artificial solids, in which the nanocrystals take the place of atoms in traditional solids. This thesis reports the utility of field-effect transistor measurements to elucidate charge transport parameters, such as charge carrier density and charge carrier mobility in a nanocrystal solid. The evolution of these parameters with chemical treatments is followed and correlated to improved performance in photovoltaic devices. Chemical treatments are demonstrated to simultaneously engineer interparticle spacing, doping and electronic coupling in nanocrystal solids. The nanocrystal solids are then utilized as building blocks for fabricating all nanocrystal heterostructure. A type-I nanocrystal heterostructure is fabricated to demonstrate efficient electroluminescent device in the infrared communications wavelength. The device emits at peak wavelength of 1.58 um with an effciency of 0.5%.

A novel current-sensing circuit that can operate from 1MHz to 4MHz has been designed and implemented for high-frequency low-power dc-dc power converter applications. The design is based on SenseFET concept with embedded SenseFETs in the main switch (MS) and synchronous rectifier (SR). An intermediate RC filter merges outputs from the MS and SR SenseFETs and supplies a smooth voltage signal to an op-amp. This reduces the need for a very high gain-bandwidth op-amp circuit and improves the efficiency of the power converter. The circuit has configurable feedback gain in order to increase current sensing accuracy when the average inductor current is small.

This thesis encompasses a theoretical analysis, the fabrication, and optical characterization of a novel compact Bragg Slot Waveguide with a Cavity (BSWC). Strong light confinement in the low refractive index slot region formed by two silicon slabs on a silicon dioxide substrate [1] makes this structure useful for optofluidic, sensing, and optical trapping applications. The transmission spectrum of the BSWC can be engineered through the dimensional variations of the waveguide and through the refractive index change of the surrounding medium. BSWC is compact and can be integrated with various components on a chip for increased functionality. The results in this thesis show a good agreement between analytical and experimental results, while emphasizing the increasing importance of atomic-scale imperfections as a result of fabrication on the nano-scale. The impact of the slot width, slab width, and the cavity length on the waveguide transmission spectrum is investigated.

This thesis encompasses a theoretical analysis, the fabrication, and optical characterization of a novel compact Bragg Slot Waveguide with a Cavity (BSWC). Strong light confinement in the low refractive index slot region formed by two silicon slabs on a silicon dioxide substrate [1] makes this structure useful for optofluidic, sensing, and optical trapping applications. The transmission spectrum of the BSWC can be engineered through the dimensional variations of the waveguide and through the refractive index change of the surrounding medium. BSWC is compact and can be integrated with various components on a chip for increased functionality. The results in this thesis show a good agreement between analytical and experimental results, while emphasizing the increasing importance of atomic-scale imperfections as a result of fabrication on the nano-scale. The impact of the slot width, slab width, and the cavity length on the waveguide transmission spectrum is investigated.