Origin of high bandwidth performance of graded-index plastic optical fibers

Abstract

Observations in high bandwidth graded-index plastic optical fibers (GI POFs) are reported of strong mode coupling and its characteristic square root-like fiber length dependence of the optical pulse broadening. We have further found that the measured refractive index profile is not parabolic, but consists of two markedly different regions. Analysis of the index profile reveals that strong mode coupling increases the GI POF bandwidth from its profile-determined value of 0.43 GHz to its measured value of 3.0 GHz for 100 m.

Effects of Random Perturbations in Plastic Optical Fibers

“…A GI POF provides a multimode waveguide in which modal dispersion is compensated by both mode coupling and the graded index (7,8). The GI profile is formed by interfacial gel polymerization in a solid preform before fiber melt drawing (15).…”

“…or mode mixing (4-6). Recent experiments on POFs in our research group have revealed unanticipated large enhanced bandwidths due to random index perturbations and mode coupling (7,8), which is our main topic here.Modal dispersion in the optical fiber waveguide is reduced through mode coupling by allowing the energy packets of the input signal pulse to occupy different modes at different times as they are propagating down the waveguide. These conditions can occur by way of random perturbations along the propagation direction of the fiber ~vaveguide.…”

“…or mode mixing (4-6). Recent experiments on POFs in our research group have revealed unanticipated large enhanced bandwidths due to random index perturbations and mode coupling (7,8), which is our main topic here.…”

Theoretical analysis on the preparation of gradient-index polymeric rods by a centrifugal field

“…Duijnhoven et al 18 reported than the condition for forming a GI rod by a centrifugal field must satisfy the following equation: Ͼ 10,000 d Ϫ0. 5 . In this study, the radius is 0.5 cm.…”

“…[1][2][3][4][5][6] The theoretical attenuation limit of perfluorinated (PF) GI polymer optical fiber (POF) has been estimated to be as low as 0.3 dB/km, which is comparable to that of a silica fiber in the near-infrared region. 1 GI POF based on PF polymer with a transmission speed as high as 11 Gb/s at 1.3 m was reported recently.…”