Measurement of large convex hyperbolic mirrors using hindle and stitching methods

Based on the traditional Hindle-Sphere method and Subaperture stitching method, we introduce a measurement method for large convex hyperbolic mirrors. This method uses a small sphere to get the subaperture's surface shape of the convex hyperbolic mirror, and then uses the stitching method to get the full-aperture surface shape. The experimental demonstrations were performed on a convex hyperbolic mirror with our method. The results show that the repeatability of the RMS is 0.002λ (3σ). Compared with the traditional optical compensation method, it is shown that our results are in good agreement with it. Our method can get high-precision full-aperture surface shapes; furthermore, the cost of maintaining it is relatively low and the operation is convenient.

► A new measurement method for large convex hyperbolic mirrors is introduced. ► The sphere parameters considered are the convex mirrors and stitching effects. ► The sphere parameters are given by equations, and the stitching theory is in the matrix form. ► The new method can obtain the full-aperture surface shape with satisfactory accuracy.