Anisotropic semiconducting thin films have attracted attention in recent years for important applications such as electrical interconnects, electronic sensors, field-emission devices and thermoelectric devices. However, the characterization of the full conductivity tensor, especially the cross-plane conductivity, remains a great challenge for anisotropic thin films. In addition, the synthesis of large-area...
Meeting the exploding demand for wireless data services will require access to new wireless spectrum. However, the traditional approach of clearing spectrum and reallocating is becoming increasingly difficult. This in turn has led to much interest in new approaches for sharing spectrum among different users, such as the those being...
Amorphous In-Ga-Zn-O (a-IGZO) and other amorphous oxide semiconductors are attracting increasing attention from the display industry for their high electron mobility, ease of large-area manufacture, and potential for future flexible electronics. However, such amorphous materials often show instability under gate voltage bias, temperature, and illumination stress, with extremely slow relaxation...
By 2020, there will be more than 200 billion sensor enabled objects world-wide in the Internet of Things (IoT). The biggest challenge of future IoT is to provide ultra scalable wireless access for a massive number of devices. The goal of this thesis is to build up a model for...
Short-wave infrared (SWIR) photon detection has become an essential technology in the modern world. Sensitive SWIR detectors with low noise levels, and high signal-to-noise-ratios are highly desirable for a variety of applications including light detection and ranging, optical tomography, and astronomical imaging. As such many efforts in infrared detector research...
Recent advances in optical switching have yielded an all-fiber, all-optical, device capable of routing single-photon quantum signals at high rates (≈25 GHz), with almost immeasurably small degradation of the quantum state[1, 2, 3]. These switches can facilitate complex quantum networking and quantum information processing schemes. However, the complexity of these...
This dissertation focuses on exploring novel light steering and spectral engineering functionalities by flat optics, which includes photonic architectures of flat plasmonic metasurfaces, nanoparticle arrays, and thin film coatings. We have designed, fabricated and characterized different plasmonic metasurfaces (trapezoid-shaped antennas, nanorings/nanowires, etc.), nanoparticle arrays (single-layered or multilayered nanocubes and nanodisks),...
In this dissertation, we start with the dictionary learning (DL) based single-frame super-resolution (SR) problem, where low resolution (LR) input frames are super-resolved to high resolution (HR) output frames. We propose to extend the previous single-frame SR methods to multiple-frames, i.e., estimating single HR output frame by multiple LR input...
Optical interferometry is a powerful technique which has been widely utilized for well over a century in making the world’s most precise measurements. By measuring how the interference between two waves is affected by a physical process, one can deduce the magnitude of this process. Because the wavelength of a...
Agents of online platforms often have to make purchase decisions in the face the uncertainty of the true value of an item. Observing the other agents’ actions and/or reviews is one common method to learn about an item. However such observational learning can lead to an information cascade, in which...