Indirect Pump Scheme for Quantum Cascade Lasers

Masamichi Yamanishi
Central Research Laboratories, Hamamatsu Photonics KK

Thursday, October 21, 2010 at 10:45am
Engr IV Maxwell Room 57-124

Abstract

We review theoretical and experimental results on indirectly pumped mid-infrared quantum cascade lasers. In particular, high device-performance of a long-wavelength (~15 ?m), InGaAs/InAlAs, Fabry-Perot quantum-cascade laser based on the indirect pump scheme (IDP) is exhibited: a low threshold-current-density of ~3.5 kA/cm2, a high maximum output power of ~216 mW, and a high slope efficiency of ~346 mW/A, all at room-temperature. The observed extremely high characteristic temperature of threshold current, T0~450 K over wide temperature range, 320~380 K is ascribed to strong suppression of electron populations in injectors, which are specifically visualized in the IDP. The feasibility of the IDP scheme for high temperature (> 250 K) operation, without the assistance of high magnetic fields, of THz quantum cascade lasers is discussed.

Biography
Masamichi Yamanishi received the B.S., M.S. and Doctor degrees, all in electrical engineering from the University of Osaka Prefecture, Osaka, Japan, in 1964, 1966, and 1971, respectively. In 1966, he joined the Department of Electrical Engineering, the University of Osaka Prefecture, as a Research Associate. In 1979, he was appointed as an Associate Professor with the Department of Physical Electronics, Hiroshima University, Hiroshima, Japan, and in 1983, he was promoted to a Full Professor. He was a Visiting Professor (Sabbatical Chair) with Purdue University, West Lafayette, IN, in 1984, 1986, 1987, and 1991. From 1998 to 2001, he was the Dean of the newly established Graduate School of Advanced Sciences of Matter, Hiroshima University, and from 2001 to 2003, was the Vice President with Hiroshima University. Since his retirement from Hiroshima University in 2004, he has been a Chief Scientific Adviser (full time) with Central Research Laboratories, Hamamatsu Photonics KK., Hamamatsu, Japan. He is also a Professor Emeritus with Hiroshima University. He was involved in experimental and theoretical research on surface-acoustic-wave devices, 2-D distributed-feedback lasers, theory of polarization dependence of optical transitions in semiconductor quantum-well structures, theory of gain-spectra of semiconductor lasers based on non-Markovian relaxation dynamics, linear and ultrafast nonlinear electro-optic effects of semiconductor quantum-well structures, their applications to high-speed field-effect semiconductor optical devices including the first demonstration of field-effect light emitters, proposed by himself, quantum manipulation of spontaneous emissions in semiconductor micro-cavities, THz-electro-magnetic wave generation by polarized-exciton-polaritons in micro-cavities, photon-number squeezing in semiconductor light-emitting diodes. His current research interests include quantum cascade lasers and meta-materials.

Dr. Yamanishi is a Life Fellow of IEEE and a Fellow of the Japan Society of Applied Physics, a member of the Physical Society of Japan and the Laser Society of Japan, and an Editorial Advisory Board Member of Laser Focus World, Japan. From 1996 to 1998, he was the Far-East Editor, International Journal, Progress in Quantum Electronics (Elsevier Science). He is a recipient of Optics and Quantum Electronics Award of the Japan Society of Applied Physics in 2001 and the 60th Cultural Award of the Cyuugoku Shinbunsya (a News Paper Company in Hiroshima area) in 2003.