WHAT DOES BIREFRINGENT CRYSTAL MEAN?

各向异性透明晶体如方解石、石英等的折射率，是其固有的特性，称为永久双折射。In Just about every frame of Figure eight, the axis of your microscope polarizer is indicated via the cash letter P which is oriented within an East-West (horizontal) route. The axis of the microscope analyzer is indicated by the letter A