Interconnect characteristics of fiber image guides

Abstract

We investigated various factors that influence the transmission of high-density and high-bandwidth signals propagated through fiber image guides. The effects of signal power uniformity, optical cross talk, mode dispersion, and modal noise were considered. A model for power uniformity and optical cross talk is provided that we used to evaluate the channel density of several coupling modes. Also, modal noise was experimentally measured for several conditions of coupling to the fiber image guide. A commercially available fiber image guide was evaluated in the context of these performance considerations and was experimentally tested. The resultant minimum signal channel based on these criteria was found to consist of three fiber elements. The limit on transmission length that is due to modal dispersion was estimated at 1.65 m at 2.5-Gbits/s and at 42 cm at 10-Gbits/s data rates. Optical cross talk and modal noise were found to place a lower limit on the signal channel density. These characteristics compare favorably with electrical interconnect densities that are projected for tape automated bonding and flip-chip bonding techniques used at the chip-to-module and chip-to-board packaging levels.