Infrared and Laser Engineering, Volume. 53, Issue 10, 20240240(2024)
Design of refractive-diffractive hybrid medium wave infrared thermal suppression optical system in a wide temperature range
Figures & Tables(20)
Fig. 4. Diagram of mid-wavelength infrared optical system structure
Fig. 5. Spot diagram of optical system in different fields of view
Fig. 9. (a) MTF curve of optical system designed at 20 ℃; (b) MTF curve of optical system designed at 90 ℃; (c) MTF curve of optical system designed at 150 ℃; (d) MTF curve of optical system designed at 220 ℃
Fig. 11. Relationship among diffraction efficiency, temperature, and wavelength
Table 1. The corresponding optical and thermal properties of medium wave infrared optical materials
View tableView in ArticleTable 1. The corresponding optical and thermal properties of medium wave infrared optical materials
Characters/Trademark Refractive index at 4 μm Td/ 10−6·℃−1 dn/dT/ 10−6·℃−1 Cr/ ×10−3 Td/ 10−6·℃−1 Cd/ ×10−3 Si 3.42 63.44 160.00 1.98 5.2 −0.26 ZnS 2.26 25.13 39.70 5.036 13.20 −0.26 ZnSe 2.43 31.98 55.96 2.86 15.20 −0.26 GaAs 3.31 79.60 195.17 3.13 13.00 −0.26 AMTIR1 2.51 37.27 74.57 2.32 24.00 −0.26 AMTIR3 2.62 22.20 52.8 2.76 28.00 −0.26 IRG22 2.51 32.66 60.00 2.38 25.00 −0.26 IRG24 2.62 −7.00 21.14 2.22 40.00 −0.26 IRG25 2.60 24.61 62.00 2.68 28.00 −0.26
Table 2. System technology index
View tableView in ArticleTable 2. System technology index
Parameter Value Wavelength range/μm 3.7-4.8 Focal length/mm 55 F number 2 Field angle/(°) 10×8 Working temperature/℃ 20-220 Value of MTF ≥0.5 Value of relative distortion ≤3%
Table 3. Optical element parameters of an ideal optical system
View tableView in ArticleTable 3. Optical element parameters of an ideal optical system
Element $\varphi $ h/mm Lens1 0.0409 13.75 Lens2 − 0.0274 11.73 Lens3 0.033 −7.5 Diffraction plane 0.0142 −7.5 Lens4 0.0191 −7.5
Table 4. The eight material combinations with the smallest distances in the objective lens group
View tableView in ArticleTable 4. The eight material combinations with the smallest distances in the objective lens group
Serial number Combination Distance/10−6 ·℃−1 1 IRG24/ZnS 24.44 2 AMTIR-3/ZnS 26.53 3 IRG25/ZnS 31.86 4 Si/GaAs 43.507 5 ZnSe/IRG22 43.92 6 ZnS/IRG22 47.29 7 ZnS/AMTIR1 55.52 8 ZnSe/AMTIR1 67.88
Table 5. The eight material combinations with the smallest distances in the relay lens group
View tableView in ArticleTable 5. The eight material combinations with the smallest distances in the relay lens group
Serial number Combination Distance/10−6·℃−1 1 IRG22/IRG24 (diff) 1.08 2 GaAs/IRG22 (diff) 3.71 3 AMTIR1/IRG24 (diff) 4.89 4 ZnSe/IRG24 (diff) 7.30 5 AMTIR1/ZnSe (diff) 8.62 6 AMTIR1/AMTIR3 (diff) 8.83 7 Si/GaAs (diff) 10.66 8 IRG25/IRG24 (diff) 12.02
Table 6. 20-220 ℃ focus shift of system
View tableView in ArticleTable 6. 20-220 ℃ focus shift of system
Temperature/℃ Focus shift/mm +20 + 0.0078 +90 − 0.0076 +150 −0.017 +220 −0.027
Table 7. The angle of incidence and the corresponding diffraction efficiency
View tableView in ArticleTable 7. The angle of incidence and the corresponding diffraction efficiency
Angle of incidence/(°) Diffraction efficiency 0.00 100.0000% 17.21 99.99% 34.37 98.93% 51.56 93.20% 68.75 77.68% 90.00 51.47%
Table 8. Preset tolerance value
View tableView in ArticleTable 8. Preset tolerance value
Parameter Value Surface tilt/(°) ±0.03 Surface decenter/mm ±0.015 Element tilt/(°) ±0.05 Element decenter/mm ±0.01 Thickness/mm ±0.02 Radius/Fringes ±2
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Yuan PENG, Hongda WEI, Yang LIU, Jianwen ZHANG, Weijie DENG, Qiang FU. Design of refractive-diffractive hybrid medium wave infrared thermal suppression optical system in a wide temperature range[J]. Infrared and Laser Engineering, 2024, 53(10): 20240240
Paper Information
Category: 光学设计
Received: Jun. 3, 2024
Accepted: --
Published Online: Dec. 13, 2024
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