| 摘要 |
A modulated index lens containing a subsurface zeroth order coherent microlenticular mosaic defined by an index gradient adds a normalizing function to the vergences or parallactic angles of incoming light rays subtended from field object points and redirects them, in the case of near-field images, to that of far-field images. Along with a scalar reduction of the lense's linear focal range, this results in an extreme depth of field with a narrow depth of focus and when used as an intraocular lens (IOL) or contact lens avoids the focal split-up, halo, and inherent reduction in contrast of multifocal IOLs and multifocal contact lenses. A high microlenticular spatial frequency, which, while still retaining an anisotropic medium, results in a nearly total zeroth order propagation throughout the visible spectrum. The curved lens surfaces still provide most of the refractive power of the lens, and the unique holographic fabrication technology is especially suitable for contact lenses, artificial corneas, and miniature lens elements for cameras and other optical devices. The holographic projector system has many other uses such as for the fabrication of directional light filters, microlens arrays, and highly corrected submicron patterning on curved surfaces.
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