In a self-consistent field formalism we investigated the weak-probe optical intersubband response of a three-subband semiconductor quantum well pumped by a strong coherent laser beam. We showed that, when the pumping photon energy is somewhat above the energy separation between the two lowest subbands, a combination of hole-burning effects and coherent pump–probe wave interactions can lead to both optical gain without population inversion and an Autler–Townes-like doublet in the probe optical spectrum. These two absorption peaks, whose positions are blueshifted as the pump intensity is increased, are due to the two-photon absorption process and light-induced intersubband transitions between the two upper states. It is also demonstrated that, in a stepwise two-photon pumping scheme, the optical gain with population inversion can also occur in the quantum-well system when a modestly strong pump field is present.
© 1998 Optical Society of AmericaFull Article | PDF Article
More Like This
Ansheng Liu and Cun-Zheng Ning
J. Opt. Soc. Am. B 17(3) 433-439 (2000)
Danhong Huang, Cunkai Wu, and Yang Zhao
J. Opt. Soc. Am. B 11(11) 2258-2265 (1994)
J. Opt. Soc. Am. B 15(2) 586-593 (1998)