Abstract

 

Due to the small size and compactness and capability of direct modulation of the optical output by electric current, semiconductor lasers have found applications in many areas such as telecommunication, optical fiber communication, optical data storage and reading . An advanced type of semiconductor lasers is a quantum dot (QD) laser. A significantly improved performance (particularly, high temperature stability of operation) is anticipated from such lasers in view of the spatial confinement of carriers in all the three dimensions in nanosize QDs. Different factors can contribute to the temperature dependence of threshold current of a QD laser. In this work, the effect of internal optical loss has been studied and shown to set an upper limit for operating temperatures of a QD laser and considerably reduce the characteristic temperature - a figure of merit of injection lasers. The internal loss also constrains the shallowest potential well depth and the smallest tolerable size of a QD, beyond which no lasing can be attained. At the maximum operating temperature or as any parameter of the structure approaches its critical tolerable value, the characteristic temperature reduces to zero.

 

Biography

Li JIANG received his B.S. degree in Physics from Peking University in 2001 and M.S. degree in Microelectronics and Solid-State-Electronics from the Institute of Semiconductors of the Chinese Academy of Sciences in 2004. He is currently pursuing his Ph.D. degree under the direction of Dr. Asryan. His work focuses on the theory of semiconductor quantum dot lasers.