Enhancement of absorptive optical nonlinearity of asymmetrically coupled quantum well structures
Hu Zhen-Hua (胡振华)ab, Huang De-Xiu (黄德修)a
a Department of Optoelectronics Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; b Department of Physics, Wuhan University of Technology, Wuhan 430063, China
Abstract The third-order nonlinear susceptibility $\chi ^{({3})}$ of asymmetrically coupled quantum well (ACQW) structure is calculated by employing a V-type three-level model. The efficiency of absorptive optical nonlinearity, which we define as the ratio of the third-order nonlinear susceptibility $\chi ^{({3})}$ to the linear absorptive coefficient $\alpha_0$, is analysed for different electronic coherence oscillation frequencies. We show that the efficiency is enhanced with the increase of the electronic coherence oscillation frequency between the two wells but is degenerated as that of a single quantum well when the electronic coherence oscillation frequency is zero. Compared with single quantum well, the ACQW designed has the property of nonlinear absorption and dispersion depending strongly on the external electric field along the growth direction. We predict that ACQW structures can provide both high efficiency limiters and controllable optical Kerr switch in future communication systems.
Received: 12 July 2004
Revised: 08 December 2004
Accepted manuscript online:
Fund: Project supported by the State Key Development Programme for Basic Research of China (Grant No G20003605)
Cite this article:
Hu Zhen-Hua (胡振华), Huang De-Xiu (黄德修) Enhancement of absorptive optical nonlinearity of asymmetrically coupled quantum well structures 2005 Chinese Physics 14 812
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