Patent ID: 6760134
Filing Date: 2004-07-06
Classification: G02B,G03H

Abstract:
A real-time true-color holographic imaging system for a selected target, wherein said system includes:a first optical platform; red, green and blue laser light generators mounted on said platform, each generator including, a colored laser producing a main straight and narrow input beam centered on a main optical axis; a main beam splitting means centered at the end of said main axis to form substantially equal first and second co-dependent beams from said main beam, defining coextensive and normally extensive axes therewith, respectively, from said end; a beam folding reflector means centered at the end of said second axis to form a third beam, said third beam defining an axis parallel to said coextensive axis; an acousto-optical modulator (AOM) means centered on said coextensive axis to change the optical frequency of first beam by n megahertz in response to an n megahertz carrier signal, where n is different for each of said generators; first and second passive optical beam expander lens means centered on said coextensive and parallel axes, respectively to increase and equalize the diameter of said first and third beams, thereby establishing a predefined system, aperture; and at least one convex passive optical lens means centered on one of said coextensive and parallel axes to refocus the wave-front of one of said first and third beams from flat to spherical; and wherein said system further includes: a radio frequency oscillator means coupled between said AOM means for generating three different carrier signals at frequencies of n=r, n=g and n=b mHz; a beam combining means to redirect said first and third beams of all of said laser light generators into a single tri-color FZP (Fresnel Zone Pattern) beam centered on a shared optical axis with an output end from which said FZP beam emerges; an electronic scan signal generating means to create two periodic, orthogonally and harmonically related, sawtooth electronic scan signals, the longest period of which defines a complete scan cycle; a motorized scan reflector means centered at said output end and electronically coupled to said scan signal generating means to redirect said input FZP beam into a raster pattern that covers the entire exposed surface of said target during each complete scan cycle and to redirect a tricolor FZP return beam; reflected back from said target to said scan reflector and onto said shared axis; a secondary beam-splitting reflector means centered on said shared axis adjacent said scan reflector means to further redirect said return beam to a detection axis intersecting said shared axis, while passing at least a portion of said input FZP beam unreflecteded; an opto-electronic detector means centered on the end of said detection axis to generate a wide frequency band output current proportional to the optical amplitude variations of said return beam; three electronic primary band-pass filters coupled in parallel to the output of said detector to separate said complex current into three narrow frequency band color currents each centered on a different carrier frequency of n; a demodulating circuit means coupled to the output of each of said filters and a corresponding output of said radio frequency oscillator means to multiply the signals from said outputs together and three electronic secondary band-pass filters each coupled to the output of a different demodulating circuit means and designed to pass only the lower sideband signals from that output as a primary color video signal; a signal processor means coupled to the outputs of said secondary filters and said scan signal generator means to synchronize, integrate and store said scan signals with said video signals in a TV type storage medium.