Optical array generation and interconnection using birefringent slabs

The use of double refraction in cascaded slabs of birefringent media for generating arrays of beams or spots is described. Arrays containing 2(n) beams are obtained for each incident beam by use of n cascaded slabs. The density, redundancy, and coherence of existing beam arrays can be modified with this technique. Input beams with spatially nonuniform amplitudes may be used, and both efficiency and array uniformity can exceed 95%. This approach is also useful for optical interconnection and can produce many patterns of beam location and polarization. Interconnects including compact split-andshifts can be realized, and reconfigurable weights or patterns are also possible. The low dispersion of many birefringent materials makes this technique useful for broad-spectrum or wavelength multiplexed arrays. Trade-offs in the implementation are discussed, and experiments demonstrating the technique are presented.