Arbitrary distribution of refractive-index and birefringence can be realized artificially with the subwavelength structured surface. Various optical elements with subwavelength structure have been developed . The recent trends of studies on the subwavelength optical elements are toward the processing technologies for commercial production and the new applications. An optical lens with antireflection structured surface and a formbirefringence quarter-wave plate were fabricated with

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... ing or hot-embossing methods . A microretardar array was used as a key device of the polarization imaging camera system.