Hello, 

I would like to conduct a sensitivity analysis on the optical axis orientation of birefringent crystals. I am asking the manufacturer to cut a birefringent crystal so the optical axis is at 45-deg w.r.t the optical axis. x-cosine, y-cosine and z-cosine set the optical axis orientation of the uniaxial optical axis. In my case, x-cosine and z-cosine are set to 0.707 and y-cosine is set to 0. To conduct the sensitivity analysis, I thought I'd slightly change those values but I am not sure that is right. Has anybody done this before? any advice please?

Thanks!

Driss