CDS Prism

This prism is constant deviation dispersing prism which is important in spectroscopy. It is known as Pellin – Broca prism.In CDS prism, angle of incidence is equal to angle of emergence and the angle of deviation is 90°, a ray would be passing through a position of minimum deviation. This principle is used in CDS.m=1.673 - 1.717 (Approximate)