Hi,

I have the problem in loss.

I am using my own material index values for core and cladding (silica clad). Is it required to fit the material using “fit material with coefficient model” or not. if so why we have to do the procedure. In the following pcf https://kb.lumerical.com/en/diffractive_optics_pcfibre.html they choose without material fitting using corning silica, and the results explained according to that (bending the fiber). the figure bend radius vs loss is decreasing is satisfied.

(I will take mesh cells more like 500, and pml conditions like LMA fiber optimized conditions)

give me exact notation I have to consider the fitting model or not.?

thanks in advance