Abstract

Ultrafast scattering times in the femtosecond range are expected to lead to unusual and interesting optical properties in semiconductors. In particular, free carrier absorption becomes a competing process with respect to interband absorption. Due to the ultrafast scattering time, the homogeneous spectral broadening is very large and momentum is not conserved in optical transitions. However, the time evolution of the photoexcited carriers can be followed closely and information on the mobility in transient states can be gained from optical measurements.

© 1990 Optical Society of America