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The domain inversion in RuO2:LiNbO3 crystal wafer by the digital holographic interferometry is quantitatively studied. The crystal wafer is placed into one arm of a Mach-Zehnder-type interferometer to record a series of holograms. An unexpected phase contrast adjacent to the domain wall is measured and the influence of the external voltage on it is studied.

One-dimensional perfect-shuffle networks are extended to two-dimensional perfect-shuffle networks, and this extension is analyzed by means of the finite-state model. The routing algorithm presented is based on quaternary numbers for 4 X 4 switches, and its extension to k X k switches is briefly discussed. In order to take full advantage of the three-dimensional interconnection capability and two-dimensional space-bandwidth product of free-space optics, we map one-dimensional perfect-shuffle networks into two-dimensional perfect-shuffle networks, with both having 4 X 4 switching elements. Finally we compare the permutation capability of two-dimensional perfect-shuffle networks with one-dimensional perfect-shuffle networks.

A modified gamma network that is based on the bar-plus-2(super i) and modulo-N connection patterns is proposed. The gamma network, one class of important O(N log(sub 2) N) interconnection networks, needs arrays of 1 X 3 or 3 X 3 switches, which makes it difficult to realize in optics. We modify the gamma network to meet the characteristics of optics by employing a bar-plus-2(super i) connection pattern and a modulo N output stage. Two-by-two switches and regular interconnections are used in the network, so the network is suitable for optics. The optical implementation of the network with a birefringent crystal and an array of programmable half-wave plates is suggested, and a proof-of-principle experiment is presented. The network is a rearrangeable nonblocking network, and the nonblocking routing algorithm for an N X N network is given; (2 log(sub 2)N - 2) switching stages (with a total of (2 log(sub 2)N + 1/2)N - 4 log(sub 2) N - 1 switches) can permute N input nodes to N output nodes in any order in a one-to-one manner. The network is applicable to packet synchronous optical traffic.

The optical logic-operated moire is a new method to extract a specific moire pattern. It has the capabilities of eliminating original carrier frequencies, increasing the contrast, and narrowing the fringes. We introduce its applications in moire topography and deflectometry and also present the experimental results.

Based on the dual-rail encoding concept, beam splitting, and beam combining, an optical logic gate capable of performing all 256 logic functions of three input binary patterns is proposed. The gate is programmed by polarization customizing. The full adder and the full subtractor are thus suggested, and the experimental results are presented.

The LiNb[O.sub.3] crystals by digital holographic interferometry is used to phase map the domain kinetics under the uniform steady-state electric field. The results from the phase mapping of individual domain nucleation and growth in the two crystals revealed that both longitudinal and lateral domain growths are not linear during the electric poling.