Splice loss evaluation for optical fibers with arbitrary-index profile.

A method is presented for calculating offset and tilt losses for fiber splices with axially symmetric arbitrary-index profiles by approximating the profile with a staircase function. This method is applied to a large-core dual-mode fiber with zero intermodal dispersion as well as to single-mode fibers with step- and parabolic-index profiles. When a splice loss of 0.2 dB is permitted, the normalized offset misalignment is found to be D(N) = 0.635 for the dual-mode fiber at normalized frequency v = 4.605 and a power-law exponent alpha = 4.5. The D(N) value compares favorably with the values 0.560 and 0.614 for conventional step- and parabolic-index single-mode fibers, respectively. The dual-mode fiber is superior to the step- and parabolic-index fibers with respect to permissible splice offset tolerances.