Fig. 1. Gull-wing aspheric optics. (a) Sample piece; (b) gull-wing surface divided into central convex and outer concave at inflection point

Fig. 2. Subaperture division based on transformation between global coordinate system and local coordinate system

Fig. 3. Subaperture division for gull-wing surface

Fig. 4. Scanning measurement path planning. (a) Central ring subaperture; (b) first ring off-axis position subaperture; (c) overlapping region of central ring subaperture and first ring off-axis position subaperture; (d) measurement path planning of central ring and first ring; (e) measurement path planning of full aperture

Fig. 5. Three-dimensional model diagram of scanning measurement platform

Fig. 6. Flow chart of scanning stitching measurement

Fig. 7. Calculation diagram of overlapping point pair matching

Fig. 8. Gull-wing aspheric surface measurement site

Fig. 9. Partial subaperture measurement results. (a1)(a2) Central subaperture; (b1)(b2) first ring off-axis position subaperture; (c1)(c2) second ring off-axis position subaperture; (d1)(d2) third ring off-axis position subaperture

Fig. 10. Full aperture profile error result

Fig. 11. Comparison of line profile measurement results. (a) profile result of full-aperture profile error line; (b) measurement result obtained by profiler

Fig. 12. CGH compensator test comparison experiment. (a) CGH compensator test site; (b) CGH profile test result; (c) profile test comparison in same area

Table 1. Parameters of surface shape

Table 2. Specifications of standard objective lens with 1024 pixel×1024 pixel detector array

Table 3. Design parameters of subaperture for gull-wing surface