Theoretical analysis was applied to analyze the refractive-index distribution (RID) and bandwidth (BW) of gradient-index polymer optical fibers (GI POFs) prepared by a centrifugal field process. The RID of the prepared GI POF could be represented by the equation of <i>n</i>(<i>r</i>) = <i>n</i><sub>1</sub>[1 − 2δ(<i>r</i>/<i>a</i>)<sup><i>g</i></sup>]<sup>1/2</sup>. The studied material systems were poly(hexafluoroisopropyl 2-fluoroacrylate) (PHFIP 2-FA)/dibutyl phthalate (DBP) and poly(methyl methacrylate) (PMMA)/benzyl benzoate (BEN). The RID and the BW were significantly affected by an essential parameter <i>k</i>, which was related to the material properties (density difference and molecular weight) and processing properties (rotating speed, temperature, and radius). As <i>k</i> increased, the characteristic constant of RID, <i>g</i>, decreased to a minimum and then increased sharply, owing to the separation of the polymer and the dopant. On the other hand, the relative refractive-index difference of RID, δ, increased to a steady value after <i>k</i> increased to a certain value. The variation of RID with <i>k</i> resulted in a local minimum of intermodal dispersion, and thus a maximum bandwidth was obtained. The maximum BW of the PHFIP 2-FA/DBP and PMMA/BEN systems at 1550 nm (100-m fiber length and 2-nm spectral width) for the case of <i>k</i> ≠ 0 were 6.7 and 3.2 Gb/s, respectively. The wavelength of light source affects the BW significantly only at <i>k</i> around zero because of the importance of the intramodal dispersion in this case.
© 2003 Optical Society of America
(000.4430) General : Numerical approximation and analysis
(060.0060) Fiber optics and optical communications : Fiber optics and optical communications
(060.2290) Fiber optics and optical communications : Fiber materials
(060.2400) Fiber optics and optical communications : Fiber properties
(160.0160) Materials : Materials
Ming-Hsin Wei and Wen-Chang Chen, "Theoretical Analysis on the Refractive-Index Distribution and Bandwidth of Gradient-Index Polymer Optical Fibers from a Centrifugal Field," Appl. Opt. 42, 2174-2180 (2003)