Influence of numerical aperture on mode coupling in step-index plastic optical fibers.

Using the power-flow equation, we have examined the state of mode coupling in step-index plastic optical fibers with different numerical apertures. Our results confirm that the coupling rates vary with the coupling coefficient of the fibers as the dominant parameter, especially in the early stage of coupling near the input fiber end. However, we show that the fiber's numerical aperture has a significant influence on later stages of this process. Consequently, equilibrium mode distribution and steady-state distribution are achieved at overall fiber lengths that depend on both of these factors. As one of our examples demonstrates, it is possible for the coupling length of a high-aperture fiber to be similar to that of a low-aperture fiber despite the three-times-larger coupling coefficient of the former.

[1]  L. Jeunhomme,et al.  Numerical Solution of the Coupled-Power Equation in Step-Index Optical Fibers , 1977 .

[2]  G. Jiang,et al.  Mode coupling and equilibrium mode distribution conditions in plastic optical fibers , 1997, IEEE Photonics Technology Letters.

[3]  R. D. Standley,et al.  The length dependence of pulse spreading in the CGW-Bell-10 optical fiber , 1973 .

[4]  D. Gloge,et al.  Optical power flow in multimode fibers , 1972 .

[5]  D N Payne,et al.  Mode conversion coefficients in optical fibers. , 1975, Applied optics.

[6]  A. Djordjevich,et al.  Principles of deflection-curvature measurement , 2001 .

[7]  Gao,et al.  Effects of random perturbations in plastic optical fibers , 1998, Science.

[8]  S. Savović,et al.  Investigation of mode coupling in step index plastic optical fibers using the power flow equation , 2000, IEEE Photonics Technology Letters.

[9]  Alexandar Djordjevich,et al.  Optical power flow in plastic-clad silica fibers. , 2002, Applied optics.

[10]  J P Pocholle,et al.  Propagation model for long step-index optical fibers. , 1976, Applied optics.

[11]  V. Ruddy,et al.  Mode coupling in large-diameter polymer-clad silica fibers. , 1995, Applied optics.

[12]  Gotzon Aldabaldetreku,et al.  New method to calculate mode conversion coefficients in SI multimode optical fibers , 2003 .

[13]  J. Hannay,et al.  Ray theory and random mode coupling in an optical fibre waveguide. II , 1976 .

[14]  Joseba Zubia,et al.  Mode coupling contribution to radiation losses in curvatures for high and low numerical aperture plastic optical fibers , 2002 .

[15]  Solution of mode coupling in step-index optical fibers by the Fokker-Planck equation and the Langevin equation. , 2002, Applied optics.

[16]  A. Mickelson,et al.  Distributed loss and mode coupling and their effect on time-dependent propagation in multimode fibers. , 1993, Applied optics.