Study on the optical property of the micro Fabry-Perot cavity tunable filter

摘要

Pushbroom Hyperspectral Imager (PHI) is a new intensively researched subject in the spectral imaging field.Hyperspectral imaging is getting wide attention due to their high spectral resolution. The conventional imaging spectrometer uses prism and grating as dispersive component. As the Fabry-Perot (F-P) cavity has high resolution and excellent frequency selectivity, in this paper, MEMS F-P array filter is used as the light splitting device. It is compact,fast modulate rate, high precise and easy to be integrated. In this paper, the optical property of the integrated micro F-P cavity tunable filter has been studied. Optical thin film design software TFCalc has been adopted to design the optical thin film of the micro filter. Design and analysis of antireflection coatings, high reflection and the F-P cavity interference filter. The test results show that the optical properties of the fabricated samples are consistent with the design results. In order to simulate the working mechanism of the micro F-P cavity, two filters were fixed together to form an F-P cavity.The filter effect of the F-P cavity was tested using a spectrometer, the comb filter pattern was observed. The feasibility of the optical F-P cavity tunable filter is confirmed.