Two species of Mantis Shrimp have been reported to be able to detect circular polarized light.
2.
Elliptical polarized light ( violet ) is composed of unequal contributions of right ( blue ) and left ( red ) circular polarized light.
3.
When E R equals E L ( when there is no difference in the absorbance of right-and left-circular polarized light ), ? is 0?and the light is circularly polarized.