Improvement of saturation optical intensity in electroabsorption modulators with asymmetric intra-step-barrier coupled double strained quantum wells

Department of Electrical Engineering, Faculty of Electrical and Computer Engineering, Shahid Beheshti University, G.C. 1983963113, Tehran, Islamic Republic of Iran

^a e-mail: k_abedi@sbu.ac.ir

Received: 3 March 2011
Accepted: 12 August 2011
Published online: 28 September 2011

Abstract

In this article, the saturation optical intensity in electroabsorption modulators (EAMs) at 1.55 μm with asymmetric intra-step-barrier coupled double strained quantum well (AICD-SQWs) active region is theoretically investigated and compared with intra-step quantum well (IQW) structure. For this purpose, the two basic escape processes, thermionic emission and tunneling, are considered and the escape times of photogenerated carriers both for the AICD-SQW and the IQW based on the InGaAlAs material system are calculated and compared. From the reduction in escape times, improvement in the saturation optical intensity due to the introduction of the AICD-SQW structure is estimated to be greater than 6 dB at high fields.