Research on compensation detection method for high-order convex aspheric surface
The high-order convex aspherical mirror is a crucial element in the optical system,and usually used as a secondary mirror to compensate for the off-axis aberration of optical systems,however,its inspection method has always been a major challenge.The back-to-zero detection method is adopted,and a combination of three lenses and a single refractive surface is proposed to compensate for the normal aberration of the high-order aspheric surface.Firstly,the quadratic comparison surface of the high-order aspheric surface is selected to simplify the calculation.Based on the third-order aberration theory,the initial structure of the system is solved,and the normal aberration of the high-order aspheric surface is compensated.After simulation and optimization using ZEMAX software,it is shown that the design results fully meet the requirements.And then,combined with a high-order convex aspheric reflector with an effective clear aperture of 170 mm and a vertex curvature radius of 266.8 mm,the root mean square of the mirror's surface shape accuracy is measured to be 0.019 λ(λ= 632.8 nm),which meets the actual detection requirements and verifies the feasibility of the proposed design method.This method provides a new idea for the inspection of large-diameter high-order convex aspheric surfaces.
geometric opticshigh-order convex aspheric surfacezero compensationthird order aberration