Abstract

The two-photon absorption (TPA) in semiconductors and the nonlinear index of refraction n, associated with it have recently attracted the attention of many researchers because of their potential application in a wide range of optical devices.¹ Recently, we have shown that low-dimensional structures (LDS), such as quantum wells, wires, and boxes, offer the benefits of a modified density of states.² This results in the enhancement of the two-photon nonlinearity and also in its anisotropy. It is well known that because of quantum confinement, excitons in LDS are more robust than those in bulk material. .Moreover, their impact on optical properties is quite remarkable, LDS tend to possess a sharp density of states and a correspondingly enhanced oscillator strength of excitonic states. This makes the LDS an attractive choice for nonlinear optical devices based on two-photon processes.

© 1994 Optical Society of America