The modular interference characteristics of circular-core and elliptical-core two-mode fibers are investigated in theory. The intensity distribution and figure of two-lobe mode patterns are evaluated and simulated quantitatively for different phase difference change between LP01 and LP11^(even) mode. The interference mode patterns of elliptical-core and circular-core two-mode fibers are compared, the result shows that the two-lobe interference patterns of the two-mode fibers generate energy exchange and oscillation, and the difference is that the interference mode patterns of circular-core two-mode fiber are almost elliptical, while the interference mode pattern of elliptical-core two-mode fiber is approximately circular on condition that proper selection of the ellipticity. Their two-dimensional (2D) profile determines the choice of the core shape of the information pick-up fiber.
© 2006 Chinese Optics LettersPDF Article