Abstract

Picosecond pulses from a mode-locked dye laser were used in an excite-probe configuration at room temperature (Fig, 1), with excite and probe beam powers of 200 and 20 µW, respectively. Both beams were polarized to produce mutually orthogonal linear polarizations, the same circular polarizations, or opposite circular polarizations. The sample was fabricated by molecular-beam epitaxy with a p-type background doping of 10^th cm⁻³ etched to remove the GaAs substrate. It consisted of 120 periods of 65-Å quantum wells with 212-Å Al_0.4Ga_0.6 As barriers.

© 1993 Optical Society of America