Lynford L. Goddard
Assistant Professor
2254 Micro and Nanotechnology Lab
lgoddard@illinois.edu
217-244-0799
Graduate Students
Ben Griffin
My research centers on the design, fabrication, and characterization of laser based chemical sensors. I have been primarily focused on the detection of trace gases, specifically hydrogen, using thin palladium films integrated within the structure of several types of lasers. These lasers include edge emitting lasers, vertical cavity surface emitting lasers, and distributed Bragg reflector lasers. When the integrated palladium film comes in contact with hydrogen gas, it forms palladium-hydride, which possesses a different complex index of refraction from the pure metallic palladium. When the mode from the laser interacts with the integrated palladium film, the output power and wavelength from the laser shift as a function of hydrogen concentration. This ability to quickly detect small concentrations of hydrogen is crucial for the adoption of hydrogen fuel cell technology, due to the lower explosive limit of 4% hydrogen in air. Additionally, these same structures can be easily modified to detect a variety of different gases for other applications.
griffi14@illinois.edu
2251 MNTL
Young Mo Kang
My research work is mainly on analysis, simulation, design, engineering, and fabrication of microring resonators integrated with distributed Bragg reflector (DBR-MRR). The DBR-MRR is a new family of reflective devices developed in our lab that combines the compact footprint of the microring and the selective reflection spectrum of the Bragg grating. The buildup of field strength in the ring resonator configuration yields multiple reflection encounters with the same set of grating, enabling the DBR-MRR to achieve high reflectivity with only a few pairs of low index contrast grating and makes possible compact narrow-band reflectors, switches, and filters for dense integration in photonic devices.
ykang7@illinois.edu
2251 MNTL
Amir Arbabi
I work on theory, design and numerical simulation, fabrication, and measurement and characterizing reflective microring resonators. Reflective microring resonators are compact narrowband optical reflectors with high reflectivity that have potential applications in photonic integrated circuits and in particular narrowband tunable laser diodes.
arbabi1@illinois.edu
2251 MNTL
Chris Edwards
My research interests include lasers, photonics, MEMS, and imaging systems. Before transferring to the University of Illinois, my research focused primarily on control theory and robotics. My first semester here, I worked mostly on device testing. Over the course of the next year and a half, I worked on the design and optimization of palladium-coated VCSELs for hydrogen sensing applications. During the spring of 2011, I worked on a fiber-optic interferometer for hydrogen sensing and the design and construction of an environmental stabilization chamber. My current research, which also began in the spring of 2011, focuses on imaging systems and quantitative phase imaging (QPI) techniques (SLIM, DPM, etc.) in order to investigate the dynamic behavior of nano-scale phenomena.
edward31@illinois.edu
2231 MNTL
Steve McKeown
I am interested in fiber based sensors for trace gas detection and the measurement of other physical properties.
mckeown3@illinois.edu
2231 MNTL
Onyeama Osuagwu
My research involves the theoretical development, simulation, design and fabrication of novel photonic devices for optical data and signal processing. I am currently investigating nonlinear optical phenomena in micro ring resonators as part of this goal.
osuagwu1@illinois.edu
2251 MNTL
Renjie Zhou
I am studying interference microscopy for wafer defect detection.
rzhou5@illinois.edu
2231 MNTL
Ching-Ying (Josephine) Lu
My work is mainly on fabrication and testing of microring resonators integrated with distributed Bragg (DBR-MRR). The DBR-MRR is a replacement for a linear DBR. It can get a single wavelength reflection, reduce the number of gratings, and suppress side lobes in the reflectance spectrum. However, its performance is limited by non-ideal fabrication where sidewall roughness of the devices increases the radiation loss and causes unwanted reflection at other ring resonance wavelengths. Therefore, I am investigating several smoothing techniques. Fabricated devices are then tested to demonstrate the effectiveness of the smoothing techniques.
lu18@illinois.edu
2231 MNTL
Undergraduate Students
Manan Raval
My main project involves the testing of thin films of palladium when exposed to hydrogen. Exposure to hydrogen alters the physical properties of the palladium, specifically by changing the refractive index of the material. Because of this property, palladium can effectively be used in hydrogen sensors. Since hydrogen is flammable at concentrations as low as 4%, it is very important to have accurate sensors that can detect such low concentrations of the gas, such as in cases of hydrogen leakages. I use a reflection/transmission setup to test these thin film samples of palladium. Ideally, changes in these two properties when the sample is exposed to hydrogen should directly correspond to changes in the concentration of hydrogen in the surroundings. I am also helping with some other projects, such as laser testing, waveguide loss measurements, and circuitry for a temperature stabilization chamber used for laser testing.
raval2@illinois.edu
2231 MNTL
Jerry Zhou
I am measuring reflective microring resonators.
zhou60@illinois.edu
2231 MNTL
Ping-Keng (Steve) Lu
I'm working on laser noise modeling.
plu6@illinois.edu
2251 MNTL
Yu Yan
I am working on an instrument amplifier circuit and doing laser testing.
yuyan1@illinois.edu
2231 MNTL