Physical interpretation of intercore crosstalk in multicore fiber: effects of macrobend, structure fluctuation, and...

To estimate the intercore crosstalk in uncoupled multicore fibers with cores' propagation constants perturbed by bending, twist, and structure fluctuations, in the paper [Opt. Express21, 5401 (2013)10.1364/OE.21.005401] entitled "Physical interpretation of intercore crosstalk in multicore fiber: effects of macrobend, structure fluctuation, and microbend," Hayashi et al. derived an intuitively interpretable expression of the average power-coupling coefficient as the convolution of the arcsine and Lorentzian distributions, and calculated the derived expression numerically by performing the fast Fourier transform. In the present paper, we derive a closed-form solution of the convolution of the arcsine and Lorentzian distributions, and point out that the closed-form analytical expression derived here is exactly equivalent to the previously reported closed-form expression.