High-resolution nearly degenerate four-wave mixing in Nd-doped β” alumina

R. L. Abrams, Jenny Lam, Richard C. Lind +2 more

S. Catherine Weaver, Stephen A. Payne

Stephen Colby Rand, Jenny Lam, R. Steven Turley +2 more

We report the first observation of the nearly degenerate four-wave--mixing spectrum of ${\mathrm{Nd}}^{3+}$-doped \ensuremath{\beta}''-Na-alumina. In a new application of continuous-wave high-resolution nearly degenerate four-wave mixing, a linewidth analysis of \ensuremath{\sim}1-kHz-wide optical resonances in heavily doped samples has been used to explain concentration-dependent, nonradiative decay of Nd ions which is obscured in conventional fluorescence-decay studies. Quantitative four-wave--mixing saturation studies also reveal a transition between a ``closed'' and an ``open'' quantum system due to pair interactions at a Nd density of \ensuremath{\sim}6\ifmmode\times\else\texttimes\fi{}${10}^{20}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$.

Juan Francisco Lam

The quantum evolution from a closed to an open system, induced by collisional processes, is presented in the framework of nearly degenerate four‐wave mixing (NDFWM) spectroscopy. We show that an open system manifests itself by the appearance of a subnatural linewidth in the spectrum of the phase conjugate signal. Examples are described for sodium vapor in the presence of buffer gases and in Nd+3 doped β‘‐Na‐Alumina for high concentration of Nd+3 ions.

Duncan G. Steel, Richard C. Lind, Jenny Lam +1 more

Robert W. Boyd, Bruce Dunn, Dongliang Yang +3 more

Nd3+ beta″ alumina is one of a family of potentially useful nonlinear-optical materials based on rare-earth ions substituted into a beta″ alumina host. The saturation intensity of Nd3+ beta″ alumina has been measured to be in the range 16 to 35 kW cm−2. Phase conjugation by degenerate four-wave mixing has been demonstrated, and the phase-conjugate reflectivity has been measured as a function of both laser wavelength and intensity.