Recording of colour holograms on photosensitive material using illumination in stages by several different coherent wavelengths along common path to record interference fringes

摘要

A recording of the object (17) may be made by successively increasing wavelengths or simultaneously at the different wavelength sun a single layer photosensitive support (18), where three wavelengths are used, 488nm, 532nm and 610 nm may be selected. A reflector (9) is placed in the bram of each of the sources (5-7) in turn to send the beams along the common path (16). Alternatively, one reflector and two partial reflectors and transmitters enable three simultaneously beams. Fibre optic cables may be used with a pair of two-input couplers two produce a single beam in an optical fibre directed towards the object.