Abstract
In view of the fact that the bandwidth required in optical fiber communication systems will exceed 100 Gb s(-1), ultrafast optical switching and modulation devices with high efficiency must be developed. Given that intersubband transitions (ISBT) in quantum wells (QWs) are one of the important ultrafast phenomena, a numerical study of intersubband transition (ISBT) properties in (CdS/ZnSe)/BeTe QWs is considered. The structure modeled consists of a few monolayers of CdS embedded in a ZnSe/BeTe QW. A self-consistent analysis is made to achieve the desired properties and device applications. Variation of CdS well thickness leads to tailoring of the band alignment, achieving optical transitions in the wavelength range of 1.33-1.55 mu m wavelengths for applications in optical fiber transmission. To analyze the optical behavior of the heterostructure under investigation, we have calculated the CdS well thickness-dependant oscillator strengths and electron emission energy of the intersubband transition between the two first states in the well. An attempt to explain our results will be presented.