Robust Population Inversion by Polarization Selective Pulsed Excitation

Abstract

The coherent state preparation and control of single quantum systems is an important prerequisite for the implementation of functional quantum devices. Prominent examples for such systems are semiconductor quantum dots, which exhibit a fine structure split single exciton state and a V-type three level structure, given by a common ground state and two distinguishable and separately excitable transitions. In this work we introduce a novel concept for the preparation of a robust inversion by the sequential excitation in a V-type system via distinguishable paths.

Optical power limiting of ultrashort hyper-Gaussian pulses in cascade three-level system

“…[23][24][25][26][27][28][29][30] For example, shaped pulses have been used to enhance the transient population of excited states and to obtain maximum population inversion; [23][24][25][26] the anti-Stokes and Stokes generations can be tailored into a variety of forms in Raman-resonant four-wave-mixing process by manipulating the phase relationship among relevant electromagnetic fields; [27,28] the propagation dynamics of a femtosecond chirped Gaussian pulse and the population distribution in a dense three-level Λ-type atomic medium can be manipulated by changing the sign and size of the chirp coefficient; [29] the robust population inversion against pulse area variation in a V-shaped three-level system can be created by resonant excitation with cross-polarized laser pulse pairs. [30] The effect of temporal pulse shape on the strong field quantum dynamics involving ultrashort few-cycle pulses has always been one of the focuses of attention of scientists. [31][32][33] The attosecond electron dynamics and the ultrafast popu-lation transfer processes in few-state atomic and molecular systems can be coherently manipulated according to the requirements by using the ultrashort pulses of different field envelopes.…”