Dear community,
I am currently looking into the confinement losses with respect to wavelength for different fiber types: SIF, PCF, ... . To check my models for the simplest type (SIF) I found a publication from Kubat et al., "Mid-infrared supercontinuum generation to 4.5 um in uniform and tapered ZBLAN step-index fibers by direct pumping at 1064 or 1550 nm ," J. Opt. Soc. Am. B (2013) who showed the confinement losses for a ZBLAN fiber accross a wavelength range from 1 to 5 micron for different core diameters. I attached an adapted graph from the paper as Confinement losses.png below.
I took the Sellmeier coefficients from another paper and used a cylindrical PML to account for confinement losses. The simulation runs fine, the dispersion curve determined from the effective refractive index is the same as determined from the eigenvalue equation, but the confinement losses in z-direction (emw.dampzdB) does not correspond to the one in the paper. My confinement loss (in the model for 4 micron diameter) sets in roughly one micron later than in the publication. As they also used COMSOL and have more experience with the software I guess I have the suspicion that I did something wrong. My first thought that sth. went wrong with the PML [does the width actually haven an influence?], but I am not sure. Does someone have an idea? As the model was too large (even without mesh) I uploaded it here: www.dropbox.com/s/yn815et2wpw04qz/SIF-ZBLAN1.mph?dl=0
Thank you very much in advance,
Bernd![]()
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I am currently looking into the confinement losses with respect to wavelength for different fiber types: SIF, PCF, ... . To check my models for the simplest type (SIF) I found a publication from Kubat et al., "Mid-infrared supercontinuum generation to 4.5 um in uniform and tapered ZBLAN step-index fibers by direct pumping at 1064 or 1550 nm ," J. Opt. Soc. Am. B (2013) who showed the confinement losses for a ZBLAN fiber accross a wavelength range from 1 to 5 micron for different core diameters. I attached an adapted graph from the paper as Confinement losses.png below.
I took the Sellmeier coefficients from another paper and used a cylindrical PML to account for confinement losses. The simulation runs fine, the dispersion curve determined from the effective refractive index is the same as determined from the eigenvalue equation, but the confinement losses in z-direction (emw.dampzdB) does not correspond to the one in the paper. My confinement loss (in the model for 4 micron diameter) sets in roughly one micron later than in the publication. As they also used COMSOL and have more experience with the software I guess I have the suspicion that I did something wrong. My first thought that sth. went wrong with the PML [does the width actually haven an influence?], but I am not sure. Does someone have an idea? As the model was too large (even without mesh) I uploaded it here: www.dropbox.com/s/yn815et2wpw04qz/SIF-ZBLAN1.mph?dl=0
Thank you very much in advance,
Bernd