Author Affiliations
1Key Lab of Modern Optical Technologies of Education Ministry of China, School of Optoelectronic Science and Engineering, Soochow University, Suzhou, Jiangsu 215006, China2Key Lab of Advanced Optical Manufacturing Technologies of Jiangsu Province, School of Optoelectronic Science and Engineering, Soochow University, Suzhou, Jiangsu 215006, China3Beijing Institute of Space Mechanics & Electricity, Beijing 100190, China;show less
Fig. 1. Optical layouts of VIS-IR imaging spectrometer. (a) Front view; (b) side view
Fig. 2. Schematic of multi-zone grating
Fig. 3. Diffraction efficiency of multi-zone grating. (a) VIS-NIR grating; (b) IR grating
Fig. 4. LightTools analysis model
Fig. 5. Schematic of order-sorting filter. (a) VIS-NIR channel; (b) IR channel
Fig. 6. Illuminations of different diffraction light in image plane of VIS-NIR channel. (a) -1 order diffraction light of VIR-NIR grating; (b) -2 order diffraction light of IR grating; (c) -3 order diffraction light of IR grating
Fig. 7. Reflectance curve of coating
Fig. 8. Illuminations of different diffraction light in image plane of VIR-NIR channel after stop coating. (a) -1 order diffraction light of VIS-NIR grating; (b) -2 order diffraction light of IR grating; (c) -3 order diffraction light of IR grating
| Parameter | Value |
|---|
| VNIR | IR |
|---|
| Spectral range /nm | 400--1000 | 1000--5000 | | Spectral resolution /nm | 3.6 | 9.6 | | F | 6 | 3 | | Slit length /mm | 10 |
|
Table 1. Main parameters of system
| Wavelength /μm | Chief ray position /mm |
|---|
| N1=-1 | N1=-2 | N1=-3 | N2=-1 | N2=-2 | N2=-3 | N2=-4 |
|---|
| 0.4 | 0 | 3.33 | 6.67 | -2.13 | -0.93 | 0.27 | 1.48 | | 0.55 | 1.25 | 5.83 | 10.43 | -1.68 | -0.03 | 1.63 | 3.28 | | 0.70 | 2.50 | 8.34 | 14.19 | -1.23 | 0.88 | 2.98 | 5.09 | | 0.85 | 3.75 | 10.84 | 17.97 | -0.78 | 1.78 | 4.33 | 6.89 | | 1.00 | 5.00 | 13.36 | 21.78 | -0.33 | 2.68 | 5.69 | 8.70 |
|
Table 2. Chief ray position at each diffraction order in image plane of VIS-NIR channel
| Wavelength /μm | Chief ray position /mm |
|---|
| N1=-1 | N1=-2 | N1=-3 | N2=-1 | N2=-2 | N2=-3 | N2=-4 |
|---|
| 1.00 | 0 | 2.99 | 5.98 | 8.98 | 11.98 | 5.30 | 13.61 | | 2.00 | 3.00 | 8.99 | 14.99 | 21.03 | 25.61 | 13.62 | 30.57 | | 3.00 | 5.99 | 15.00 | 24.08 | 33.54 | - | 21.99 | - | | 4.00 | 8.99 | 21.04 | 33.54 | - | - | 30.57 | - | | 5.00 | 11.99 | 27.17 | 47.72 | - | - | 40.36 | - |
|
Table 3. Chief ray position at each diffraction order in image plane of IR channel
| Diffraction order | Illumination /(W·mm-2) |
|---|
| Wavelengthof 1.00 μm | Wavelengthof 0.85 μm | Wavelengthof 0.70 μm | Wavelengthof 0.55 μm | Wavelengthof 0.40 μm |
|---|
| -1 order of VIS-NIR grating | 1.73×10-5 | 2.84×10-5 | 2.83×10-5 | 3.23×10-5 | 1.96×10-5 | | -1 order of IR grating | 1.18×10-7 | 1.17×10-7 | 9.45×10-8 | 1.27×10-7 | 1.44×10-7 | | -2 order of IR grating | 4.70×10-8 | 5.71×10-8 | 1.83×10-5 | 6.83×10-6 | 3.56×10-5 | | -3 order of IR grating | 2.49×10-5 | 1.26×10-5 | 3.02×10-5 | 2.66×10-5 | 1.22×10-7 | | -4 order of IR grating | 9.58×10-6 | 6.99×10-7 | 5.92×10-6 | 1.28×10-7 | 9.62×10-9 | | Total illumination caused by IR grating | 3.47×10-5 | 1.36×10-5 | 5.45×10-5 | 3.37×10-5 | 3.59×10-5 | | Diffraction stray light coefficient | 200.53% | 47.64% | 192.24% | 104.28% | 183.46% |
|
Table 4. Analytical results for diffraction stray light in image plane of VIR-NIR channel
| Wavelength /μm | 0.40 | 0.55 | 0.70 | 0.85 | 1.00 |
|---|
| Distance /mm | 0.120 | 0.233 | 0.340 | 0.450 | 0.555 | | Maximum bandwidth /nm | 42.1 | 69.22 | 94.9 | 121.3 | 146.5 |
|
Table 5. Distance between -1 order diffraction light spot of VIR-NIR grating and -3 order diffraction light spot of IR grating on detector window glass
| Diffraction order | Illumination /(W·mm-2) |
|---|
| Wavelengthof 0.40 μm | Wavelengthof 0.55 μm | Wavelengthof 0.70 μm | Wavelengthof 0.85 μm | Wavelength of 1.00 μm |
|---|
| -1 order of VIS-NIR grating | 3.11×10-5 | 3.55×10-5 | 3.35×10-5 | 3.11×10-5 | 1.41×10-5 | | -1 order of IR grating | 0 | 4.85×10-9 | 1.36×10-8 | 1.39×10-8 | 8.70×10-9 | | -2 order of IR grating | 8.14×10-8 | 9.25×10-9 | 8.55×10-9 | 2.34×10-8 | 2.08×10-8 | | -3 order of IR grating | 4.82×10-10 | 4.88×10-8 | 8.81×10-8 | 2.36×10-8 | 6.08×10-9 | | -4 order of IR grating | 0 | 4.42×10-14 | 1.03×10-8 | 1.09×10-12 | 4.40×10-8 | | Total illumination caused by IR grating | 8.19×10-8 | 6.29×10-8 | 1.21×10-7 | 6.10×10-8 | 7.97×10-8 | | Diffraction stray light coefficient | 0.26% | 0.18% | 0.36% | 0.19% | 0.57% |
|
Table 6. Analytical results for diffraction stray light in image plane of VIS-NIR channel after stop coating
