Abstract

The microscopic understanding of coherent light-matter interactions is an important goal of solid-state physics which can be exploited in ultrafast optoelectronics. One of the most fundamental coherent effects is that of Rabi oscillations, whereby a strong resonant field induces temporal oscillations of the electron density between ground and excited state.¹ This effect has been studied extensively in atomic and molecular two-level systems. Although, semiconductors differ from ideal two-level systems due to mutual interactions of the extended electronic excitations, modified Rabi oscillations have been predicted theoretically to occur also in semiconductors.² However, the short relevant time scales make experimental observation difficult. In previous studies the observations were limited to one or two density maxima due to ultrafast scattering times below 100 fs.^3,4QMC5 Fig. 1. (a) Pump-probe configuration for a 6-band semiconductor quantum well, (b) Linear transmission spectrum of the ln„ |Ga_0VAs/GaAs multiple quantum well at 5 K. (c) Spectra of pump and probe pulses generated by two optical parametric amplifiers.

© 1999 Optical Society of America