CONTROL SYSTEM FOR COMPOSITE INCIDENT BEAM

摘要

PROBLEM TO BE SOLVED: To make the beam of a high space bandwidth product face the different areas of the surface of a hologram memory cell(HMC) by controlling the direction of the beam made complex incident on a spatial modulation of coherent light to execute the access to the data location of the HMC. SOLUTION: The focal distance of a lens 304 is (f1). Then, the Fourier transformation of an object to be inputted on a spatial modulator(SLM) 302 is formed on a Fourier focal surface 307 being distant from the lens 304 by the focal distance (f1). A rotatable mirror 306 is arranged on the surface 307 of the object to be inputted of the SLM 302. The mirror 306 is rotated by an angleθand the beam reflected by the mirror 306 is projected on the HMC 310 through a lens 308 thereafter. The Fourier object of the surface 307 is reflected on the mirror 306 so as to form the object to be inputted of the lens 308. By the lens 308, the Fourier transformation of itself is formed on the surface of the HMC 310 being distant by the focal distance (f1).