Near-hexagonal close-packed optical fiber bundle for parallel optical interconnection

Abstract

2-dimensional (2-D) near hexagonal close packed optical fiber bundle (NHCP-OFB) is proposed for parallel optical interconnection (POI). Conventionally in 2-D POI, fibers must be accurately aligned to 2-D light sources and detectors using precisely fabricated hole-plate or stacked V-grooves. It is time consuming to thread each fiber into hole-plate, as well as precisely stack the V-grooves. For polymer optical fibers with large diameter, the whole dimension of the bundle may be too huge to connect ICs if they are positioned using V-grooves or hole-plate. The purpose of NHCP-OFB is to pack the fibers closely into a 2-D lattice, and precisely positioned them at the nodes of the lattice. Due to the fluctuation of the diameter of the commercial optical fibers, it can not be packed into perfect 2-D hexagonal close packed bundle. The proposed NHCP-OFB slightly stretch the perfect 2-D hexagonal close packed bundle in one dimension and still have all fibers packed tightly with high packing fraction. The position of fibers in NHCP-OFB is very important when aligned to 2-D light sources and detectors. This paper analytically analysis the positioning offset of fibers in NHCP-OFB. The possibility distribution of positioning offset is related to variance of fiber diameter and stretched length of NHCP-OFB. Experiment samples of NHCP-OFB have been made using polymer optical fiber showing that fibers can be precisely positioned.