We have investigated the polarization-dependent two-photon absorption in GaAs/AlGaAs quantum wires. The anisotropic selection rules of the multiphoton absorption process are exploited to study the one-dimensional 2p exciton states and the transitions between quantum wire subbands of different quantum numbers (\ensuremath{\Delta} ${\mathit{n}}_{\mathit{y}}$ \ensuremath{\ne}0 selection rule). The deviations from the selection rules derived for the strict one-dimensional case are discussed, and depend on the actual quasi-one-dimensional character of the excitonic wave functions.We have investigated the polarization-dependent two-photon absorption in GaAs/AlGaAs quantum wires. The anisotropic selection rules of the multiphoton absorption process are exploited to study the one-dimensional 2p exciton states and the transitions between quantum wire subbands of different quantum numbers (\ensuremath{\Delta}${\mathit{n}}_{\mathit{y}}$\ensuremath{\ne}0 selection rule). The deviations from the selection rules derived for the strict one-dimensional case are discussed, and depend on the actual quasi-one-dimensional character of the excitonic wave functions.

Physical Review LettersAug 24, 199244 citations

QUANTUM THEORY OF POLARIZATION CORRELATION IN TWO-PHOTON EMISSION

Frederik Jozef Belinfante

Elsevier eBooksJan 1, 19730 citations

Spectroscopic Stability in Two-Photon Absorption by Atoms

Masataka Mizushima, Katsuhiko Nakahara, Tadashi Yoshida

When there exists no external field, physical results should not depend on the choice of quantization axis. This theorem is known as spectroscopic stability and is well established for one photon absorption and emission processes. In two photon absorption by a three level atom one can make the excitation of the top level forbidden if the absorption processes are restricted to one selection rule in Δ M (=+1, 0 or -1). The choice of selection rule assumes relative orientation between the polarization of the radiation field and an external field. If this relative orientation is changed the selection rule would also change and the top level would appear as a final result of two photon absorption . A question is what happens if the external field disappears in the latter case. Would the top level disappear although the selection rule stays unaltered? It is shown that the probability of having the top level disappears when the external field vanishes, confirming the spectroscopic stability and the degree of violation is obtained as a function of the strength of the external field.When there exists no external field, physical results should not depend on the choice of quantization axis. This theorem is known as spectroscopic stability and is well established for one photon absorption and emission processes. In two photon absorption by a three level atom one can make the excitation of the top level forbidden if the absorption processes are restricted to one selection rule in Δ M (=+1, 0 or -1). The choice of selection rule assumes relative orientation between the polarization of the radiation field and an external field. If this relative orientation is changed the selection rule would also change and the top level would appear as a final result of two photon absorption . A question is what happens if the external field disappears in the latter case. Would the top level disappear although the selection rule stays unaltered? It is shown that the probability of having the top level disappears when the external field vanishes, confirming the spectroscopic stability and the degree of violation is obtained as a function of the strength of the external field.

Japanese Journal of Applied PhysicsOct 1, 19891 citation

Two-photon processes

Physics TodayJan 1, 19660 citations

Three-photon bimolecular absorption

Davıd L. Andrews, Alexander M. Bittner

Three-photon bimolecular absorption is a process which, through the simultaneous absorption of three laser photons, results in the electronic excitation of two molecules or atoms. Following a recent treatment of the selection rules, a quantum electrodynamical treatment is employed to describe the main features associated with the process and to produce an equation for the excitation rate. The dependence on photon polarization is investigated, and the magnitude of the excitation rate is estimated. It is shown that two different mechanisms operate, each with different selection rules and different dependences on intermolecular separation. In each case an energy mismatch is conveyed from one molecule to the other by means of virtual photon coupling. Some possible schemes for experimental study of the process out outlined.Three-photon bimolecular absorption is a process which, through the simultaneous absorption of three laser photons, results in the electronic excitation of two molecules or atoms. Following a recent treatment of the selection rules, a quantum electrodynamical treatment is employed to describe the main features associated with the process and to produce an equation for the excitation rate. The dependence on photon polarization is investigated, and the magnitude of the excitation rate is estimated. It is shown that two different mechanisms operate, each with different selection rules and different dependences on intermolecular separation. In each case an energy mismatch is conveyed from one molecule to the other by means of virtual photon coupling. Some possible schemes for experimental study of the process out outlined.

Journal of Physics B Atomic Molecular and Optical PhysicsFeb 28, 19934 citations

{\mathit{n}}_{\mathit{y}}

\ensuremath{\ne}0 selection rule). The deviations from the selection rules derived for the strict one-dimensional case are discussed, and depend on the actual quasi-one-dimensional character of the excitonic wave functions.