Summary: | 碩士 === 國立臺灣科技大學 === 自動化及控制研究所 === 107 === The propose of this study is to design a Offner miniature spectral imager which band is 400-1000 nm. This will miniature spectrometer’s volume and increase portability. Also, decrease manufacturing cost of spectrometer. And use optics component on sales to simulate system design and imaging analysis.
First, use Optics and imaging system design analysis software CODE V to design system model. In order to decrease manufacturing cost, adjust spacing of grating to match optics component on sales. And let the imaging spot approach to diffraction limit by using wavelength 550 nm as optimization band. Finally, radius of the concave mirror is 50 mm, spacing of the grating is 3.95 μm, the Offner system size is 50 mm × 70 mm × 50 mm.
TracePro is used to simulate realistic imaging situation, and verify preliminary system design result of CODE V. The result show preliminary design is almost the same as point source with film specification in TracePro. The total spectral resolution of 0.5-1.8 nm and an image resolution of 5-7 μm. The realistic imaging situation, the result which using slit source with detector specification in TracePro show total spectral resolution of 3.1-13.5 nm and an image resolution of 22-45 μm.
In order to consider reflectance efficiency of the grating, PCGrate is used to simulate band of VNIR, the result show have most reflectance efficiency at 550 nm. Hence, select 550 nm as design parameter of grating blaze angle.
Finally, using Solidworks simulate the assembly between components to determine the feasibility of interference and system. The optical components have tolerances of 2 mm and 1 mm in the longitudinal and transverse directions respectively. And the position of the detector can be adjusted to reach the DoF range.
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