Author Affiliations
1Space Optics Technology Lab, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an, Shaanxi 710119, China2School of Optoelectronics, University of Chinese Academy of Sciences, Beijing 100049, China3School of Physics and Information Technology, Shaanxi Normal University, Xi'an, Shaanxi 710119, Chinashow less
Fig. 1. Structural diagram of system
Fig. 2. Field of view of system
Fig. 3. Shape of freeform surface. (a) Two-dimensional; (b) Three-dimensional
Fig. 4. Spot diagram
Fig. 5. Surrounding energy distributions. (a) FOV 1-5; (b) FOV 6-10
Fig. 6. Field curvature and distortion
Fig. 7. Distortion grid
Fig. 8. 80% surrounding energy distribution estimation under predetermined tolerance
Fig. 9. 80% surrounding energy distribution estimation after tolerance correction
| Parameter | Value |
|---|
| Wavelength /nm | 450-850 | | Focal length /mm | 158 | | Entrance pupil /mm | 150 | | F number | 1.05 | | Field of view /(°) | 20 | | Pixel size /(μm×μm) | 10×10 | | Detector size /(mm×mm) | 40×40 |
|
Table 1. Design parameters
| Surface | Surfacetype | Radius ofcurvature /mm | Conicconstant | Thickness /mm | Material | Aperture /mm |
|---|
| Object | Standard | Infinity | | Infinity | Air | | | 1 | Standard | 192.67 | | 25.00 | Silica _special | 210.84 | | 2 | Standard | 340.08 | | 43.62 | Air | 204.91 | | 3 | Standard | -234.44 | | 20.00 | HBAK4_CDGM | 201.76 | | 4 | Standard | 301.16 | | 6.49 | Air | 200.50 | | 5 | Quadric | 165.90 | -1.33 | 41.20 | BaF2_special | 208.61 | | 6 | Standard | -6255.80 | | 65.39 | Air | 207.58 | | 7 | Standard | 373.09 | | 20.00 | HZF6_CDGM | 189.23 | | Stop | Standard | 190.02 | | 21.10 | Air | 146.79 | | 9 | XY polynomial | 161.90 | -1.77 | 31.46 | BaF2_special | 181.10 | | 10 | Standard | -530.65 | | 5.00 | Air | 180.21 | | 11 | Standard | 204.17 | | 29.50 | BaF2_special | 168.98 | | 12 | Standard | -1068.73 | | 5.00 | Air | 165.26 | | 13 | Standard | 157.87 | | 32.23 | BaF2_special | 153.27 | | 14 | Standard | -1608.91 | | 5.00 | Air | 149.03 | | 15 | Standard | 105.36 | | 35.00 | BaF2_special | 122.04 | | 16 | Standard | -282.20 | | 15.00 | HLAK67_CDGM | 110.55 | | 17 | Standard | 52.27 | | 64.75 | Air | 77.00 | | Image plane | Standard | Infinity | | 0 | | 66.52 |
|
Table 2. System data
| Field No. | 1 | 2 | 3 | 4 | 5 |
|---|
| Field of view | (0°,0°) | (0°,5°) | (3.5°,3.5°) | (5°,0°) | (0°,7°) | | Field No. | 6 | 7 | 8 | 9 | 10 | | Field of view | (5°,5°) | (7°,0°) | (0°,10°) | (7°,7°) | (10°,0°) |
|
Table 3. Corresponding number of field of view
| Item | Coefficient |
|---|
| X2 | -0.000755341578837755 | | Y2 | -0.000755341617671267 |
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Table 4. Parameters of XY freeform surface
| Tolerance type | Tolerance value |
|---|
| Lens thickness and air gap | 0.02 mm | | Lens tilt angle | 0.001 rad | | Lens offsetting distance | 0.02 mm | | Lens wedge angle | 0.0003 rad | | Lens aperture | 2 | | Two-dimensional irregularity of lens | 0.2 | | Curvature radius (aspherical) | 0.01 mm | | Quadric surface constant | 0.001 | | Random RMS surface error (aspherical) | 0.025 | | Refractive index of material | 0.0001 | | Abbe number of material | 0.002 |
|
Table 5. Predetermined tolerance
| Tolerance type | Active surface | Expected tolerance |
|---|
| Lens tilt angle | 3 and 7 | 0.0003 rad | | Lens offsetting distance | All | 0.01 mm |
|
Table 6. Sensitive tolerance
| Proportion ofchange /% | Maximum envelopingsquare side length /μm |
|---|
| -0.50 | 20.719 | | -0.40 | 20.241 | | -0.30 | 19.849 | | -0.20 | 19.546 | | -0.10 | 19.351 | | 0 | 17.326 | | 0.10 | 18.627 | | 0.20 | 18.815 | | 0.30 | 18.883 | | 0.40 | 19.363 | | 0.50 | 19.949 |
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Table 7. Estimated maximum enveloping square side length corresponding to 80% surrounding energy distribution
