Here discloses a method for duplicating a hologram and a hologram optical element. The method comprises: preparing a master with a master hologram; preparing a sample with coated photoalignment material layer above the master; and irradiating a recording light through the sample to the master, so that at least one portion of the recording light is reflected by the master as an object light carrying the master hologram information, and so that the object light and the recording light are interfered at the photoalignment material layer to produce a duplicated hologram in the photoalignment material layer.

An identification medium can be affixed to cloth or leather products by sewing. A cholesteric liquid crystal layer on which an embossed surface for forming a hologram is formed, is sandwiched between a first supporting member and a second supporting member. A mounting region that can be affixed to clothing, etc., by sewing, is formed.

A method of manufacturing a thin film optical apparatus includes providing a substrate and applying an alignment layer over the substrate. The alignment layer ranges from about 50 to 100 nm in thickness. The method includes imprinting a hologram with a desired optic pattern onto the alignment layer and applying at least one layer of mesogen material over the alignment layer.