
{"publication_number": "US-7006266-B2", "abstract": "the invention provides an optical switcing device , including a substrate having at least one polarization - selective multiplexing grating ; at least one polarization - selective demultiplexing grating , and a polarization rotation element acting as a dynamic \u00bd \u03bb plate , optically interposed between the optical path of said multiplexing grating and said demultiplexing grating . the invention also provides a method for producing an holographic plate having a plurality of holographic elements .", "application_number": "US-39824203-A", "description": "the diffraction efficiency of a thick phase transmission hologram ( fig1 ) is given by the expression : \u03b7 = sin 2 \u2062 \u03c6 2 + \u03c8 2 1 + \u03c8 2 \u03c6 2 ( 1 ) \u03c8 \u2261 ( \u03b1 r - \u03b1 r b ) \u2062 \u2062 k \u2192 \u2062 \u2062 d \u2062 \u2062 sin \u2061 ( \u03b1 g - \u03b1 r b ) 2 \u2062 \u2062 cos \u2062 \u2062 \u03b1 s - ( \u03bb - \u03bb b ) \u2062 k \u2192 2 \u2062 d 8 \u2062 \u03c0 \u2062 \u2062 v \u2062 \u2062 cos \u2062 \u2062 \u03b1 s , ( 2 ) { overscore ( k )