Day 2 :
Keynote Forum
Taiichi Otsuji
RIEC - Tohoku University, Japan
Keynote: Single-mode terahertz lasing in current injection graphene channel transistor
Biography:
Taiichi Otsuji is a Professor at the Research Institute of Electrical Communication (RIEC), Tohoku University, Japan. He has received the PhD degree in Electronic Engineering from Tokyo Institute of Technology, Tokyo, Japan in 1994. He has worked at the NTT Labs since 1984 till 1999, Kyushu Institute of Technology from 1999 to 2005, and Tohoku University since 2005. He has authored and co-authored more than 240 peer-reviewed journal papers. He has been an IEEE Electron Device Society Distinguished Lecturer in 2013. He is a Fellow of the IEEE, a Senior Member of the OSA, and a Member of the JSAP, MRS, and IEICE.
Abstract:
Optical and/or injection pumping of graphene can enable negative-dynamic conductivity in the terahertz (THz) spectral range, which may lead to new types of THz lasers. In the graphene structures with p-i-n junctions, the injected electrons and holes have relatively low energies compared with those in optical pumping, so that the effect of carrier cooling can be rather pronounced, providing a significant advantage of the injection pumping in realization of graphene THz lasers. We fabricated a distributed-feedback (DFB) dual-gate graphene-channel transistor as a current-injection terahertz laser. A pair of teeth-brash-shaped gate electrode was patterned to form a DFB cavity in which the active gain area and corresponding gain coefficient are spatially modulated. A single mode emission at 5.2 THz was observed at 100 K beyond the threshold carrier injection level. The single mode emission exhibits a non-monotonic threshold-like behavior with the highest intensity ~10 μW, reflecting the carrier over-cooling effect under weak pumping. Spectral narrowing with increasing the carrier injection around the threshold was also observed. The result is still preliminary level but the line width fairly agrees with calculation based on DFB-Fabry-Perrot hybrid-mode modeling.
Keynote Forum
Dominique M Dagenais
National Science Foundation, USA
Keynote: Optics and photonics research programs funded by the USA National Science Foundation
Biography:
Dominique M Dagenais is currently an Acting Deputy Division Director and Program Director in the Electrical, Communication, and Cyber Systems (ECCS) Division at NSF. After receiving her Diplôme d'Ingénieur from the Ecole Supérieure d'Optique in France, she went to the Institute of Optics, University of Rochester, where she defended a thesis on uniform pellet illumination for Laser fusion. She then joined the French Atomic Energy Commission, working on high power Nd:YAG laser propagation, before coming to AVCO Everett Laboratories, where she designed beam shaping optics for CO2 lasers. She joined the Naval Research Laboratory to develop the first three-axis fiber magnetic sensor array. While at Alcatel, she supported novel devices for WDM fiber telecommunication.
Abstract:
The National Science Foundation is an independent federal agency supporting fundamental research and education across all fields of science and engineering. An overview of the National Science Foundation (NSF) will be given. This will cover NSF mission, its various programs, and the NSB merit review process, with an emphasis on the divisions supporting innovative research in Optics and Photonics. A review of the community-driven topics being funded by the NSF will be presented. We will specifically cover our portfolio of current academic research grants in the area of optical materials, photonic devices, photonic integration, optical sensors, imaging, and optical systems. Additionally, specific initiatives that may be of interest to the photonics community will be described. Finally we will briefly describe the National Science Foundation’s future directions, with its Ten Big Ideas, and how some may require new exploratory research in fundamental, cross-disciplinary photonics.