Hyperspectral infrared Fabry-Perot filter based on Fano effect

Abstract

This paper introduces the design and experiment of a new hyperspectral infrared Fabry-Perot (FP) filter based on Fano resonance. The FWHM (Full Width at Half Maxima) of the transmission peak in infrared band (1-8 μm) generated by a typical FP resonant microcavity is so large that cannot be used to achieve a common hyperspectral filtering. The FP resonant microcavity can be used to filter incident lightwave so as to generate a typical Lorentzian line pattern. Compared with the symmetric Lorentzian line shape, the Fano resonance line demonstrate a sharper character, which can be used in hyperspectral filtering imaging. In this paper, a new type of FP filter with a dentate basic structure is designed that can excite the Fano effect and generate sharp Fano resonance peak as a way to achieve hyperspectral filtering, which can be used to simulate the mechanism of Fano resonance generated in the new functioned structure developed. Then, the transmittance in the infrared band of 3 μm to 8 μm corresponding to different dentate functioned structures with different structural parameters are simulated for investigating the effect of dentate structure based on the Fano resonance. In order to verify the correctness of the simulations, he single-sided single-dentate type structure and compared the differences between the simulation and the actual measurement are fabricated and analyzed finally. The results show that the appearance of a clear Fano resonance peak observed in the designed device means that the developed goal is well achieved.