Meaning of modal Birefringence in terms of optics can be described as: The effective refractive index difference between x-polarized and y- polarized mode . However, for material inhereted birefringence can only be an assumption. Depending how you are describing the material on COMSOL this value can be varying. Briefringence of such material can be described if you are using isotropic option. İf it is anisotropic the birefringence of the material becomes more complicated to calculate.

Hi Huseyin,

Thank you very much for reply. Yes, I am not clear how to model birefringence property of Taxol in COMSOL. I also do not know the inherent value. I have seen somewhere that refractive index is about 1.64. Right now, I am trying to model known birefringence of calcite crystal using anisotropic property in comsol as diagonal matrix (nx=1.64, ny=1.44, nz=1.44). am I going in wrong way?. If I understood your reply correct way that it would be better to use isotropic medium with two different refractive index for two orthogonal polarization (we have to solve two times)?.

Thanks

Mahendar

on ısotropic media it will be fixed refractive index on all directions.

Regards

Hi Huseyin,

Thanks for reply. It was a  type error in my reply. I want to model anisotropic media. I am just doing that modelling with assumed birefringence of 0.001. nx=1.64, ny=1.639 and nz= 1.64. It am getting good response of Intensity variation with sample thickness.

Thanks

Mahnedar