期刊名称:Journal of Emerging Trends in Computing and Information Sciences
电子版ISSN:2079-8407
出版年度:2012
卷号:3
期号:6
页码:896-906
出版社:ARPN Publishers
摘要:An analytical model for the small-signal cross gain modulation (XGM) in undoped quantum dot (QD) - semiconductor optical amplifiers (SOAs) is derived using four-level rate equations model (4LREM),. The model takes into account the effect of wetting layer (WL), the continuum states (CS), excited states (ES), and the nonlinear optical gain of the dots. The calculated small-signal conversion efficiency is compared with those predicated from the three-level rate equations model (3LREM). The results show that the CS acts as a carrier reservoir for the lower energy states. Also, the reduced intersubband from the upper excited to ground state carrier relaxation time will increase the XGM conversion efficiency. The present analysis also provides insight on the escape/relaxation lifetimes of the QD amplifier which is very important for characterizing and understanding the performance characteristics of other similar-structure devices.
关键词:QD-amplifier; Wavelength conversion; Cross gain modulation