InGaAs/AlAs/InAlAs coupled double quantum wells for intersubband transition devices operating at 1550 nm

In this study, we developed InGaAs/AlAs/InAlAs-based coupled double quantum wells (CDQWs). The CDQW design was intended to obtain a high conduction band offset and to decrease the residual strain of the CDQWs. The design enabled the CDQWs to exhibit a clear 1550 nm peak of optical absorption due to the intersubband transition, and a structure in which the CDQWS were stacked 60 times was obtained. However, the optical absorption wavelength of the interband transition was slightly short for obtaining high cross phase modulation efficiency. (c) 2012 Elsevier B.V. All rights reserved.