Intersubband dynamics of holes in p-type modulation-doped Si/sub 1-x/Ge/sub x//Si multiple quantum wells

Summary form only given. Femtosecond intersubband spectroscopy provides fundamental insights into the ultrafast nonequilibrium processes of single-component, quasi-two-dimensional carrier plasmas. The time scales of intersubband scattering, thermalization and cooling are essential for understanding the relevant scattering processes and for designing novel infrared devices such as the quantum cascade lasers. While femtosecond studies focussed on electron plasmas, very limited information about intersubband dynamics in p-type quantum wells was obtained from room-temperature saturation measurements. We present an ultrafast study of hole plasmas in p-type quantum wells using direct intersubband excitation and probing of heavy-hole intersubband transitions.