Abstract

Using a unique picosecond infrared laser system we have investigated, with a pump-probe method, the saturation characteristics of the intersubband absorption in a range of multiquantum well (MQW) samples at 300K. A short- pulse Er³⁺:YSGG laser (λ=2.8 μm) pumped two travel ling-wave optical parametric generators (OPGs) which were independently tunable over the λ=3-18 μm range [1] with a 75 ps pulse duration. The “pump beam was tuned to the intersubband resonance and the “probe” scanned through the intersubband absorption feature to register spectral changes induced by the pump.

© 1996 Optical Society of America