Power Flow in Graded-Index Plastic Optical Fibers

Theoretical Investigation of the Influence of Wavelength on the Bandwidth in Multimode W-Type Plastic Optical Fibers with Graded-Index Core Distribution

“…In the numerical calculations, a Gaussian beam, P(θ,z), is assumed to be launched with θ = 0 • and standard deviation σ θ = 1.3 • (FWHM = 3.06 • ). The width of the launched beam measured at the end of a single-mode optical fiber, which is butt-coupled to the SC GI POF examined in our earlier experimental work [8], is described by this standard deviation. The numerical calculations have been performed for radial offset ∆r = 0 µm.…”

“…In this research, we investigated the bandwidth at various wavelengths in a differently constructed W-type GI POF designed from the SC GI POF (Figure 1a), which we experimentally investigated in our previously published works [8,10]. For the structure shown in Figure 1b, a W-shape refractive index model is adopted.…”

“…The normalized intermediate layer widths of δ = 0.001, δ = 0.002 and δ = 0.003 (actual width is δ•a mm) were used. In the calculations, the constant coupling coefficient d(m, λ) ≡ D = 1482 1/m was employed [8]. At λ = 476, 522, 568 and 633 nm, the maximum principal mode number in such proposed W-type GI POFs is M = 872, 795, 731 and 656, respectively.…”

“…Consider a W-type GI fiber with refractive index profile, as shown in Figure 1b. The refractive index profile of W-type optical fibers with GI distribution of the core may be expressed as [8,23]:…”

“…Studies have been reported using geometric optics (ray approximation) to investigate transmission in optical fibers [6,7]. By employing the time-independent power flow equation [2,8] as well as the Fokker-Planck and Langevin equations [9], far-field patterns in SI POFs have been predicted as a function of the launch conditions and fiber length.…”