Abstract

Iterative discrete on-axis (IDO) encoding of Fourier transform type computer-generated holograms (CGHs) to produce spot arrays has been described previously.¹ This method has been extended to encode more general Fourier transform type CGHs and to encode Fresnel holograms for optical connection networks. The IDO encoding method is based on either an iterative improvement or a simulated annealing optimization routine. It has been shown that computation time for IDO encoding is reduced by employing an iterative improvement routine and by setting the initial CGH transmittance to a pattern (determined analytically) similar to the expected near-optimum pattern. Using this method, high performance large space-bandwidth product (SBWP) holograms can be encoded in a reasonable time. Several IDO encoded holograms have been fabricated. Experimental measurements have been performed to verify computer simulation results. A Fourier transform type binary phase CGH produced a 3 × 3 array of spots with 59% diffraction efficiency.¹ Experimental Fresnel type IDO encoded binary phase optical interconnect holograms have demonstrated that high efficiency, high connection density holograms can be made.

© 1989 Optical Society of America