Central distance of interferential mode patterns of elliptical core two mode fib

By means of the weakly guiding approximation, the mode spot sizes Wx and Wy of the fundamental mode along the semimajor (x-direction) and semiminor (y-direction) axes of the fiber core in elliptical core two-mode fiber are discussed. The variation of their ratio value Wx/Wy with the operation wavelength \lambda and the length ratio a/b between the semimajor axis and the semiminor axis of the fiber core is analyzed. Based on this analysis, the distribution figures of two-lobe interferential mode