A real time
fingerprint verification system includes a recording device and a
verification device each having a
fingerprint scanner for generating a flat, dimensionally undistorted,
high contrast,
fingerprint image, and an intensity sensitive,
spatial light modulator (SLM) for receiving and transforming the flat
fingerprint image into a planar, coherent light image. In the recording device, the planar coherent light image beam of the fingerprint from the SLM is Fourier transformed, and input into a
microscope objective lens
system which expands the Fourier transformed beam image sufficiently to allow mechanical blocking of its central portion or order, whereupon it is directed to interact as an object beam with a
reference beam from the particular coherent
light source to
record a holographic
matched filter. In the
verification device, the planar coherent light image beam of the fingerprint is Fourier transformed and input into a
microscope objective lens
system to allow similar mechanical blocking of its central portion or order whereupon it is directed to interrogates a previously recorded holographic
matched filter of a
fingerprint image as an object beam for determining a match or not between the respective recorded and interrogating images. The
spatial light modulator (SLM) in both the respective recording and verification devices enables
phase correlation (
optical path length determination) of one device to another device. X-Y alignment and rotational orinentation of the respective real time image and holographic
matched filter image is accomplished by jittering (orbiting and angularly oscillating) either the interrogating object beam, real time, relative to the matched filter or visa versa.