Fourier transform lens assembly and optical information processor employing same.

摘要

A Fourier transform lens assembly suited for use in an optical information processor includes a first lens group (G1) having a positive power, a second lens group (G2) having a negative power disposed on one side of the first lens group (G1), and a third lens group (G3) having a positive power disposed on the side opposite to the first lens group (G1) with respect to the second lens group (G2). The distance between a front focal plane and a back focal plane of the Fourier transform lens assembly is less than two times a focal length of the Fourier transform lens assembly. Thus the length of the information processor is reduced. <IMAGE>