Anisotropic optics?

Maybe some of you refractor boys will have my answer- are there any optical quality/clarity anisotropic materials that have different refractive indices depending on direction of incidence? Or is this the same as birefringence?

Jess Tauber

Hi Jess,

I occasionally work with with folks who know a lot about non-linear optics and crystals that are used for doubling wavelengths of laser light. (I hope to be the first one on my block with a blue laser pointer this fall). IIRC the birefringence of some crystals (TiO2, Calcite etc.) means they have different indices of refraction for different polarization directions (hence the double image seen in these crystals), but I don't think it matters as much the angle, only the polarization.