Abstract

Nonlinear pump and probe transmission experiments were used to investigate the magnitude of nonlinear effects in CdTe/ CdMnTe quantum wells at room temperature and to examine the dynamics of carrier transfer and relaxation. The experiment was carried out at the Central Laser Facility in the Rutherford Appleton Laboratory, UK. Amplified optical pulses from a mode-locked Ti-sapphire laser were used to form the pump, and the probe was generated from a broad spectral continuum. Interference filters were used to select probe wavelengths resonant with the exciton transition. The time resolution of the system was about 300 fs. Three samples, each containing 15 wells separated by 150 Å barriers, were investigated. The well width of samples A and B was 75 Å, and that of sample C was 50 Å. The barrier composition of sample A was Cd_0.85Mn_0.15Te, and that of samples B and C was Cd_0.92Mn_0.08Te. The InSb substrate of each sample was removed using an electrochemical etch.¹

© 1994 IEEE