Ming C. Wu (Advisor)

The physical size and effective modal volume of conventional lasers with visible and near-infrared emission wavelengths are usually in the micrometer range due to the diffraction limit. The length scale of electronic transistors, however, is currently sub-100 nm thanks to the advance of fabrication technologies. For future integration of electronic and photonic devices on a chip-scale platform, we need novel laser sources that are not only compact but also capable of steering light in any direction necessary and potentially electrically injectable. In this project, a nanopatch laser...

Optical antennas are widely used in surface-enhanced Ramon spectroscopy (SERS) because of their ability to focus light in sub-diffraction-limited area, resulting in strong field enhancement. The field enhancement depends critically on the gap spacing of optical antennas. Current nanofabrication techniques such as focused ion beam milling and electron beam lithography are limited by poor uniformity and reproducibility as the dimension decreases below 10 nm, making it difficult to fabricate optical antennas with well-defined sub-10 nm gap spacing. In this project, we report on the...

There has been recent interest in low noise mm-wave signals for satellite data communication and RADAR. For these applications, close in to the carrier phase-noise performance is important. Several competing very-low-phase-noise oscillator technologies exist at lower microwave frequencies. All of these face difficulties in being extended up to the new bands of interest. We propose using an optical frequency comb generator together with an optical interleaver to up convert the low noise, low frequency microwave signal to the desired high frequency bands without increasing the phase...

Optical microring/disk resonators are the central component in many micro-optical applications, including optomechanical devices. Optomechanical devices that use light to stimulate mechanical resonance have applications in displacement sensing, optical mixing, and reference oscillators. High optical Q is necessary for these applications, so we are exploring the use of silica, which has low optical loss. So far, using a wafer-scale reflow process, we have achieved an optical Q of 15 million and have observed self-excited optomechanical oscillations. We have also fabricated nitride...