Megapixel snapshot hyperspectral imaging with high resolution Fabry-Pérot color filter array

In the field of snapshot hyperspectral imaging, a long-pursuit objective is to develop advanced spectral information encoding elements with both high spatial resolution and large sensor size. Among various strategies, Fabry-Pérot (F-P) cavity color filter, which has both high transmittance and narrow-color filtering function, represents a promising platform. However, it is extremely challenging to make F-P color filters by using multi-layer deposition method. Here, we demonstrate that a commercial-sensor-compatible F-P cavity color filter array can be fabricated through the single-step grayscale electron beam lithography. In the proof-of-concept experiment, the silver-dielectric-silver F-P color filter array, which has spatial resolution of 5.2 µm × 5.2 µm and pixel number of 1.26 million, is successfully used to demonstrate the hyperspectral imaging function. As the diameter of the electron beam is at the level of tens of nanometers, the pixel size of the F-P cavity can be down to 3.45 µm × 3.45 µm and even further. The proposed method may have great potential in high-resolution snapshot hyperspectral imaging and related applications in optical inspection, remote sensing, biomedical imaging and so on.