In the Lab...

    Most of our time in the AR Program was spent doing research in labs. Our mentors assigned us specific projects, the results of which helped them come closer to their overall research goals. My mentor was Yong-Seok Choi, a post-doctorate researcher working for the California Nanosystems Institute (CNSI). He was part of the Hu Group, lead by Evelyn Hu, who is a UCSB professor and the director of CNSI.

    My project this summer was in the research area of nanophotonics, which refers to the study of the behavior and manipulation of light at nanoscale dimensions. There are many nano devices used to manipulate light, and the Hu Group is studying these devices as separate components so that they can eventually be integrated into nanophotonic chips (microchips that use light instead of electricity). Eventually, optics will revolutionize technology as we know it and these nanophotonic chips may be the first step to replacing electrical computing systems.

    I worked with Yong-Seok Choi and another apprentice researcher named Scott Strutner to characterize microdisk resonators, one type of nanophotonic device. Microdisk resonators are very small disks (the ones we worked with were abut 10 µm) that can capture specific wavelengths of light, acting as optical filters or storage devices. These devices have much potential for improving telecommunications and making nanophotonic chips a reality.

 p.s.  I am aware that this brief overview probably makes very little sense, so please check out my final PowerPoint slides for more project information and the results of our experiments (they are available on the 2006 AR website).

This is the setup that our project revolved around. Yong set it up less than one month before we arrived, so it still needed some refining. We got to see the whole experimental process, challenges and all. Scott and I designed some new and improved parts for the apparatus that were sent to the machine shop and actually made!

The purpose of this apparatus is to get a tapered optical fiber very close (preferably within 500 nanometers) to a microdisk resonator. We use a several mirrors, lenses, and a security camera to magnify the fiber and display an image on a computer monitor.

This is the apparatus that Yong uses to taper optical fibers. Optical fibers in their normal state are made up of many layers. The blow torch in this picture burns of the plastic coating on the fibers and then heats the glass that is left so the fiber can be stretched. This process decreases the diameter of a fiber from about 120 µm to about 3 µm. We can then use the very small fiber to guide light into a microdisk resonator.

In this picture, I am attaching a plastic-encased glass fiber (the yellow "wire") to a connector which will connect it to a raw tapered fiber in our testing apparatus. The fibers, although flexible, are very delicate and we must be careful and precise in threading them into connectors and attaching them to the laser. Unfortunately, raw tapered fibers (diameter 2-5 µm) are especially fragile and several of them broke during our experiments.

Here I am working on a Lumerical FDTD simulation. We use these computer simulations to model what would happen if we were able to shine a laser through a fiber-microdisk setup with specific, known dimensions. My goal in running the simulations was to find out how the resonant mode and transmission intensity of a microdisk are affected by the gap size between fiber and disk.

Me and Yong and me and Scott! Yay!

Our lab was really cold...