New progress in analyzing Newton’s ring for testing lens surface radius of curvature

Newton’s ring is the most used tool in lens fabrication shops for testing lens surface radius of curvature. An approximate equation (Eq. (6) in this paper) is currently being widely used in optical community to calculate lens surface radius of curvature using Newton’s ring data. In a recently published paper (reference 13 in this paper), it is shown that this approximate equation contains significant errors and two high accurate simple equations (Eqs. (10) and (11) in this paper) are derived to replace this approximate equation. This paper reviews the currently widely used methods of analyzing Newton’s ring and the new progress (references 13 and 14 in this paper) in the method of analyzing Newton’s ring.