Acousto-Optics 2017: introduction to the feature issue.

The editors of Acousto-Optics 2018 provide an overview of the featured papers in the context of the 13th School of Acousto-Optics and Applications from which the articles were drawn.

Implementation of a spatially multiplexed pixelated three-dimensional display by use of a holographic optical element array.

A pixelated holographic stereogram is proposed and experimentally studied for the emulation of a spatially multiplexed composite three-dimensional (3-D) pixel display. With this approach, pixelated holograms are utilized to compose spatially multiplexed images. Each composite pixel in the holographic optical element array has a diffraction pattern that scatters light into predefined spatial directions. Under reconstruction, each pixel generates different intensities along a range of viewing angles. When the composite holographic pixel array is assembled, it has the capability to deliver 3-D effects. The technique, together with a novel recording scheme that is designed to synthesize a computerized 3-D display system based on this concept, is described in some detail.

Dual-input hybrid acousto-optic set-reset flip-flop and its nonlinear dynamics.

The characteristics of a dual-input hybrid acousto-optic device are investigated numerically and experimentally. The device, which operates as a set-reset flip-flop, uses the well-known bistable acousto-optic device with feedback to which two input beams are applied. The resulting flip-flop is analyzed numerically by use of nonlinear dynamical and nonlinear circuit-modeling techniques, and some of its properties are demonstrated experimentally.

Demonstration of acousto-optic bistability and chaos by direct nonlinear circuit modeling.

A novel technique involving nonlinear dependent sources expressed as convergent power series expansions of one or more variables representing the output fields of a Bragg-domain hybrid acousto-optic device with feedback is presented. Using some straightforward modifications of a basic circuit prototype, we show how optical bistability, possible multistability, and chaos may be generated for three fundamental types of tuning effects, i.e., feedback gain, bias voltage, and input amplitude. The results obtained are shown to compare favorably with the existing theory and experiments.

Rayleigh-Ritz optimization of the structure function for a Kolmogorov power density and an approximate analytical solution for the two-point electric field correlation function.

Beginning with the exact Kolmogorov power spectrum for an extended random medium (such as interstellar space), the structure function is first expressed as an inverse Fourier-Bessel transform. An approximate series representation involving fractional powers of the transverse coordinate is then optimized by an equivalent Gaussian expansion up to two terms using the Rayleigh-Ritz technique. The domains of validity as well as the coherence profile of the resulting analytical solution of the two-point electric field correlation function are examined. It is shown that the correlation in both the transverse and longitudinal directions persists over distances up to a few orders of magnitude greater than that for a medium described by a Gaussian structure function.

Phenomenological description of dynamic and static coherent optical effects using triple products.

A simple and straightforward application of the formalism of electronic holography to various classes of coherent optical effects is shown to confirm recently observed phenomena. Specifically, the formalism in the time domain is applied to illustrate dynamic and static pulse echoes as well as time-inverted and nontimeinverted recall of general signals, including a sawtooth and Gaussian pulse. The case of multipulse echoes, in which the echoes appear in odd order, is also explored.