Fabrication of filtering artificial-compound eye for multi-spectral imaging

Presented is a novel method for integrating the artificial-compound eye (ACE) structure with the multichannel filter on one substrate based on the microfabrication technique. By this method, a compact multi-spectral imaging lens was developed. From the point of view of the structure, it is a microlens array with the function of a filter, hence, it is called a filtering ACE. The lens has several optical units, and each unit can capture the information for a certain band which corresponds to the red, green, blue and near-infrared bands. The fabrication process and key steps are discussed in detail. Based on this filtering ACE lens, a multi-spectral imaging system was set up. The imaging results prove that the system can realise colour separation and multi-units imaging as expected. The work band of the system covers the whole visible band and a part of near-infrared band. In addition, a light blocking layer and a light separation layer were added in the filtering ACE and the image quality was improved. The novel filtering ACE structure is suitable to be applied in smart multi-spectral imaging system because of its high integration level and the ability of capturing the multi-band images.