Design, Fabrication, and Characterization of Integrated Silicon Microring Resonators
An Oral Presentation at Annual Research Conference
Anton Gribovskiy and Malik Rakhmanov
Abstract
Microring resonators are major building blocks for newly emerging silicon integrated nanophotonic circuits. These devices are widely used as narrow-band filters and efficient wavelength multiplexers for applications in biomedical research, sensor technology, and high bandwidth data transfer. The micrometer-size of such resonators is crucial for modulation of light at gigahertz frequencies. The data transfer rates above a hundred gigabits per second have already been achieved with this technology. Moreover, research is underway for microring resonators as logic elements for optical micro-processors in future all-optical computing.
Measurement of the parameters of microring resonators is important for understanding of their performance. However, very small size of such devices poses serious challenges for any such measurement. For example, the standard approach to measure the resonator line width is the ring-down technique which becomes problematic due to their extremely short storage time. Therefore, we developed a different method based on GHz modulation of light and applied it to microring resonators. We demonstrated that this method is successful for measurements of the line width of resonators. We also used this method to measure the nonlinear properties of our microring resonators.
This research consisted of three separate stages: design, fabrication, and characterization of the microring resonators, all of which we did ourselves. We used FDTD simulation to design and optimize the layout of the microring circuit. We fabricated the device on a silicon-on-insulater wafer using electron beam lithography and reactive ion etching. The fabrication part of this work was done at the Clean Room of the University of Houston. The measurements of optical properties of these devices were made in Optics and Nanophotonics Laboratory at UTRGV. This was the first time when an integrated nanophotonic circuit was designed, built, and operated at UTRGV and by UTRGV researchers.