Ming C. Wu (Advisor)

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...

We developed an optical phased array incorporating a single-layer high-index-contrast sub- wavelength grating (HCG) for 2D beamsteering. There are a number of other approaches for optical phased arrays such as liquid-crystal-based phased arrays and microelectromechanical system (MEMS) phased array. Switching of liquid-crystal based phased arrays typically takes on the order of milliseconds. Arrays of MEMS mirrors moving perpendicular to the substrate are usually made of silicon so that a metal-coated layer is required on top, resulting in thermal induced stress when very high optical...

Active III-V photonic components and passive Si photonic circuits are integrated with CMOS electronic circuits in this project. The modular MEMS-Electronic-Photonic Heterogeneous Integration (MEPHI) platform will make use of the high performance of the individual components and integrate (1) MEMS tunable VCSEL with high-index-contrast grating (HCG) mirrors, (2) photodetectors, (3) Si photonic waveguides, couplers, and interferometers, (4) high-efficiency vertical optical coupler between III-V and Si waveguides, and (5) CMOS circuits for frequency control and temperature compensation...