ANALYSIS OF A LENSED CORELESS FIBER BY A HYBRID TECHNIQUE COMBINING FD-BPM AND FD-TDM

A technique connecting a scalar wide-angle finite-difference beam-prop agation method(FD-BPM) with a scalar finite-difference time-domain met hod (FD-TDM) is systematically described and used to analyze a lensed coreless fiber. The propagating held and its phase distribution are ca lculated to demonstrate the phase adjustment effect of the lens. The p ower concentration due to the lens is evaluated by the directive gain used in the antenna engineering. The effect of an antireflection coati ng on the reflected power is also evaluated.