Abstract

Excitation of semiconductors with intense optical pulses at energies below the energy gap leads to AC-Stark shifts which yield ultrafast response times [1,2]. In principle the AC Stark shift effect persists for only the duration of the pump pulse and can therefore be used to take advantage of the very shortest optical pulses. Real excitation of carriers can accompany these virtual excitations, leaving significant densities of carriers which relax by incoherent processes on picosecond and nanosecond timescales, resulting in power dissipation and long response times. We report new experiments which elucidate the role of two-photon carrier generation by studying the AC-Stark effects in a PIN diode structure which incorporates quantum wells in the intrinsic region.

© 1988 Optical Society of America