[Reminder] Oral defense for Gary Shambat, Nov. 8th, 10AM in Clark Auditorium

Ph.D. Dissertation Defense for Gary Shambat

From Solid State to Soft Matter: Photonic Nanocavities as Advanced 

Optoelectronic Devices and Single-Cell Biomedical Probes

Advisor: Professor Jelena Vučković

Department of Electrical Engineering

 

Thursday, November 8^th 2012

10:00 AM

(Refreshments at 9:45 AM)

 

Location: Clark Auditorium (outside entrance at the very center of Clark Building)

 

Photonic nanocavities are wavelength-scale dielectric structures that possess remarkable properties due to their intrinsic small sizes and high quality factors. Simply by modifying the device materials and optical properties, one can realize nanocavities for diverse applications ranging from lasers to quantum optics and even biosensing. In this talk I will present two drastically different functions of nanocavities, both of which make them more practical for real-world adoption.   

The first half of my presentation will focus on how photonic crystal (PC) cavities can be utilized for ultra-low energy and ultra-fast optical sources for next-generation communications. To date, the true power of these nanocavities has only been demonstrated by using secondary optical control, preventing realistic integration of devices with electronics. We have therefore developed a new platform for efficiently driving PC cavities using a lithographically defined, lateral p-i-n junction. With our lateral junction we have demonstrated a world record low threshold laser with a threshold power of only 208 nW at 50K. At room temperature we find that these same devices behave as ultra-fast light-emitting diodes which can be directly modulated at up to 10 GHz. Additional active photonic devices incorporating a lateral junction will also be discussed.

The second half of my talk describes the demonstration of a whole new class of tools that marry PC cavities to the tips of optical fibers. The form factor of the optical fiber lends itself to operation of the tool in exotic environments never before accessible to a nanocavity. Specifically we have used our probes to interrogate single human prostate cells with internalized PC cavities showing, for the first time, resonant photonic modes inside biological cells. The beams can be loaded in cells and tracked for days at a time, with cells undergoing regular division and migration. Furthermore, we present in vitro label-free protein sensing with our probes as a path towards quantitative, real-time biomarker detection in single cells.