Theoretical and experimental studies of electric-field-induced refractive index change in quantum-film, -wire, and -box structures

In this article we report theoretical as well as experimental studies of the electric-field-induced refractive index change in InGaAs/InP quantum-well structures, viz., quantum-film, quantum-wire, and quantum-box structures. The refractive index change, easily measured using a Mach-Zehnder interferometer setup, was around 1%, 4%, and 7% in quantum film, quantum wire, and quantum box, respectively, in the longer-wavelength region corresponding to the positive refractive index change peak. Moreover, we will discuss that the refractive index change dependency on the polarization of incident light in a quantum film can be controlled by introducing suitable tensile strain in it. It was found that for a well width of II nm, 0.3% tensile strain should be induced to obtain polarization-independent refractive index change. (C) 1994 John Wiley and Sons, Inc.