20 September 2013

COBRA COLLOQUIUM: Friday September 20, 2013 at 15:00 – 16:00 Auditorium room 15 !!!

Speaker: Dr. Shinji Matsuo

Title: Photonic Crystal Lasers for Computercom Applications

Abstract: Lasers with ultra-low operating energy are desired for use in chip-to-chip and on-chip optical interconnects. If we are to reduce the operating energy, we must reduce the active volume. Therefore, a photonic crystal (PhC) laser with a wavelength-scale cavity has attracted a lot of attention because a PhC provides a large Q-factor with a small volume. To improve the device performance, we employ an ultra-compact embedded active region that we call a lambda-scale embedded active-region PhC laser or LEAP laser. This structure enables us to achieve effective confinement of both carriers and photons, and to improve the thermal resistance of the device. We have achieved room-temperature continuous-wave operation with threshold current of 4.8 A and the maximum 3-dB bandwidth of 16.2 GHz. The results of an experimental bit error rate measurement with a 10-Gbit/s NRZ signal reveal the minimum operating energy for transferring a single bit of 5.5 fJ. These results show the potential of this laser to be used for very short reach interconnects..

Biography: Shinji Matsuo received the B.E. and M.E. degrees in electrical engineering from Hiroshima University, Hiroshima, Japan, in 1986 and 1988, and the Ph.D. degree in electronics and applied physics from Tokyo Institute of Technology, Tokyo, Japan, in 2008.In 1988, he joined NTT Opto-electronics Laboratories, Atsugi, where he was engaged in research on photonic functional devices using MQW-pin modulators and VCSELs. In 1997, he researched optical networks using WDM technologies at NTT Network Innovation Laboratories, Yokosuka. Since 2000, he has been researching high-speed tunable lasers for photonic packet switching and photonic crystal lasers for computercom applications at NTT Photonics Laboratories, Atsugi. He is a group leader of Nano-structure Photonic Device Research Group.Dr. Matsuo is a member of the IEEE Photonics Society, Japan Society of Applied Physics and the Institute of Electronics, Information and Communication Engineers (IEICE) of Japan. He received the Opto-Electronic Integration Technology Award (Izuo Hayashi Award) in 2013.

After the colloquium (around 16:00) we organize a mini-colloquium. The speakers will be two junior colleagues from Dr. Shinji Matsuo from NTT and two COBRA researchers.

The two junior colleagues from NTT:
16:00 Hiroshi Yamazaki Linear Optical IQ Modulator for Advanced Digital Coherent Transmitter
16:15 Yuta Ueda Very-Low-Voltage Operation of Mach-Zehnder Interferometer-Type Electroabsorption Modulator

For the Photonics and Semiconductor Nanophysics Group:
16:30 Zili Zhou Ultrasensitive N-photon interferometric autocorrelator based on superconducting nanodetectors
For the Electro Optical Communication Group:
16:45 Zizheng Cao Optical True-Time-Delay Microwave Beam-Steering with Broadband Wireless Service for In-Building Networks

The audience is invited to an informal gathering following the colloquium (around 17:00) in the canteen of the Auditorium, section F!!! (see attachment)