We investigate the use of wavepacket interferometry with intersubband electronic wavepackets in suitably designed modulation-doped quantum-well structures. We study four quantum-well configurations, where the intersubband wavepackets are created by two sub-picosecond far- infrared laser pulses. By varying the delay and phase relation between the two pulses the interference between the packets and thus also the final excited state population can be controlled. The effects we discuss are purely coherent and can be used to study decoherence in intersubband transitions. Also, due to its sensitivity to the shape of the potential energy, wavepacket interferometry could be used to probe details of the potential energy, such as those caused by the presence of defects in artificially grown samples.
© 1998 Optical Society of AmericaPDF Article