Morphology measurement of cylindrical lens based on the phase deflection method

Abstract When using transmission methods to measure the morphology of cylindrical lenses, the refraction of light at the front and rear surfaces of cylindrical lenses often makes it difficult to determine the light path. To address this challenge, this paper proposes a phase deflection method based on transmission to measure the surface morphology of cylindrical lenses. This method involves calculating the displacement of points with the same phase before and after the cylindrical lens is placed in the light path, and then deriving the corresponding thickness of the cylindrical lens at these points from the displacement. The feasibility of this method has been verified through simulations. Experimental measurements of the cylindrical lens morphology were compared with the optical coherence tomography system, yielding a standard error of 5.4 μm and a root mean square error of 6.2 μm, demonstrating the effectiveness of the proposed method. Compared to existing methods, this approach significantly reduces the impact of refraction caused by the rear surface of the cylindrical lens after light transmission. Additionally, it eliminates the need for a camera lens, thereby removing the cumbersome step of camera calibration. Furthermore, interference fringes can be made very dense, enabling precise measurement of small lenses.