Experimental validation of hybrid micro-macro optical method for distortion removal in multi-chip global free-space optical-interconnection systems.

Experimental validation of a distortion removal technique for multi-chip free-space optical shuffle interconnections is presented. The free-space fabric links dense two-dimensional arrays of vertical cavity surface emitting laser(s) (VCSEL)(s) and detectors and must achieve full field registration on the order of 10 microns across the entire array. The new hybrid micro-macro optical concept realizes the required high-registration accuracy by simultaneously eliminating distortion in each of the interleaved off-axis imaging systems that comprise the complete fabric. This is achieved by exploiting the typically low numerical aperture of VCSELs. Individually tailored beam-deflecting micro-optical elements were used to create symmetry about a central aperture for VCSEL beams in the optical system. Experiments were developed to quantify the registration accuracy, the VCSEL images, and the associated spot sizes. The experimental results show that beam steering can be implemented to remove distortion in off-axis free-space optical-interconnection systems.