Events Calendar

EE-EP Seminar

Speaker: Irfan Bulu, Harvard University, School of Engineering and Applied Sciences

Talk Title: Nano-plasmonics and Nano-photonics: Applications to Enhanced Single Photon Sources, and Mid-Infrared Photonics

Abstract: Plasmonics and photonics at the nano-scale offer new possibilities for improving the performance of photonic devices such as lasers, creating new functionality, and building chip-scale integrated optical devices. In the first part of my talk, I will present our recent experimental and theoretical work on plasmonic nano-cavities for efficient, room temperature single photon sources based on nitrogen-vacancy (NV) color centers in diamond. NV center is a stable single photon source even at room temperature, and exhibits long coherence times for both electronic and nuclear spins. As a result, it is a robust quantum system for applications ranging from quantum information processing to nano-scale magnetometry. These applications benefit from large single photon rates, which can be improved by the use of nano-photonic devices. I will discuss various plasmonic cavity designs and show that the emission rate, excitation rate, and collection efficiency from single NV centers can be improved significantly in an extremely small footprint device. Furthermore, I show that our scalable, top-down nanofabrication technique maintains the crucial properties of embedded NV centers, and is therefore compatible with requirements needed for realization of quantum systems based on diamond. In the second part of the talk, I will discuss our work on mid-infrared photonics. The mid-infrared is an exciting wavelength range for on chip photonic devices, with important applications in spectroscopy and gas sensing. We recently developed record high-Q (45,000) photonic crystal cavities on a CMOS compatible platform for trace gas sensing applications. I will discuss some of the methods that we developed in order to improve the quality factors of photonic crystal cavities at mid-infrared (4.5 µm), and report the observation and origin of optical bi-stability at this wavelength range. Finally, I will discuss the prospects for future devices ranging from all-optical signal processing to on chip frequency combs at the mid-infrared.

Biography: Dr. Bulu received his Ph.D. from the department of physics at Bilkent University for his work on photonic crystals, surface plasmons, and metamaterials. He joined Professor Loncar’s lab at Harvard University as a postdoctoral fellow. Since joining Prof. Loncar’s lab, he developed efficient room temperature single photon sources based on single nitrogen vacany centers in diamond by using plasmonic nano-cavities, demonstrated optically reconfigurable photonic crystal filters, and worked on photonic crystal cavities at mid-infrared for sensing applications. He also collaborated with Schlumberger Limited and developed photonic platforms for oil and gas exploration. His current research interests include non-linear diamond nano-photonic devices for quantum information processing applications, silicon photonics at the mid-infrared wavelengths for applications in gas sensing and spectroscopy, development of new quantum emitters such as gallium nitride nanowires with embedded quantum dots/wells, and graphene plasmonics. His research resulted in more than 40 journal publications.

Host: EE-EP/USC Quantum Information and Condensed Matter Physics

Location: Seaver Science Library (SSL) - 150

Audiences: Everyone Is Invited

Contact: Marilyn Poplawski