Quantum mechanical treatment of parametric amplification in an absorptive nonlinear medium

V. I. Bespalov

Daniel F. Walls

A treatment of nonlinear optical phenomena beginning with a microscopically correct Hamiltonian containing the Bose operators of the light field and the Fermi operators for the optically active electrons in the medium is presented. Using techniques recently developed, a nonperturbative solution to the Schrodinger equation is possible. No linearization or semiclassical approximations are introduced. Two photon emission and absorption including both the degenerate and nondegenerate cases are considered. Parametric amplification and frequency conversion are investigated as examples of multiphoton processes. Atomic cooperation is shown to enhance the above phenomena. A formal treatment of a model illustrating super and subradiance is included.

N. A. Hussain

Jen‐Hao Cheng, Min Yan, Edward G. Rickey +1 more

Summary form only given. Nonlinear optical properties of an atomic medium can be modified by coherence and quantum interference that utilizes electromagnetically induced transparency (EIT). Because of the vanishing linear absorption and large enhancement of nonlinearities in an EIT medium, nonlinear optics may be studied at low light levels. We report studies of light absorption and parametric amplification based on the EIT enhanced third-order nonlinearity in a four-level atomic system. We have observed the enhanced nonlinear absorption when two coupling lasers and one probe laser are present. We are in the process of preparing the experiments for the double EIT demonstration and observation of the efficient parametric amplification in the four-level system. Because the experimental system is essentially free of Doppler broadening, quantitative comparisons between the experimental measurements and the theoretical calculations can readily be achieved.

Saeed A. Khan, A. Metelmann, Hakan E. Türeci

G. Yu. Kryuchkov, Karen V. Kheruntsyan