ERROR-CORRECTION FOR FREE-SPACE OPTICAL INTERCONNECTS - SPACE-TIME RESOURCE OPTIMIZATION

We study the joint optimization of time and space resources within fre e-space optical interconnect (FSOI) systems. Both analytical and simul ation results are presented to support this optimization study for two different models of FSOI cross-talk noise: diffraction from a rectang ular aperture and Gaussian propagation. Under realistic power and sign al-to-noise ratio constraints, optimum designs based on the Gaussian p ropagation model achieve a capacity of 2.91 x 10(15) bits s(-1) m(-2), while the rectangular model offers a smaller capacity of 1.91 x 10(13 ) bits s(-1) m(-2). We also study the use of error-correction codes (E CC) within FSOI systems. We present optimal Reed-Solomon codes of vari ous length, and their use is shown to facilitate an increase in both s patial density and data rate, resulting in FSOI capacity gains in exce ss of 8.2 for the rectangular model and 3.7 for the Gaussian case. A t olerancing study of FSOI systems shows that ECC can provide tolerance to implementational error sources. We find that optimally coded FSOI s ystems can fail when system errors become large, and we present a comp romise solution that results in a balanced design in time, space, and error-correction resources. (C) 1998 Optical Society of America.