Events Calendar

EE-Electrophysics Seminar

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

Talk Title: Quantum Plasmonics with Nitrogen Vacancy Centers in Diamond and, Mid-infrared Nano-photonics

Abstract: Diamond is an exciting material platform for nano-photonics and nano-plasmonics. It has a wide variety of stable color centers such as the nitrogen vacancy (NV) center, which is expected to be a crucial building block for solid state quantum information processing. As an optical material, diamond has a relatively large index contrast, a large Raman gain, and relatively large third order non-linear susceptibility, χ(3). My research aims to develop nano-photonic devices based on diamond and defect centers in diamond for applications in quantum information processing, all optical signal processing, and nonlinear photonics. 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 NV 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. Finally, I will discuss the future prospects for non-linear photonic devices such as Raman lasers from UV to THz frequencies, parametric oscillators, and on-chip frequency combs based on diamond.
In the second part of the talk, I will discuss our work on mid-infrared photonics. The mid-infrared (2-20 µm) is commonly referred to as the molecular fingerprint region. It is an exciting wavelength range for photonics research, with important applications in spectroscopy and gas sensing. My research aims to develop integrated on-chip photonic device platforms such as on-chip spectrometers for sensitive gas detection and spectroscopy at the mid-infrared wavelength range. A prerequisite to the realization of these applications with on-chip platforms is the development of high-Q optical cavities. 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 used 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.


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-Electrophysics

More Info: ee.usc.edu/news

Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248

Audiences: Everyone Is Invited

Contact: Marilyn Poplawski

Event Link: ee.usc.edu/news