Hyperspectral alignment capability for direct writing systems enabled by structured illumination with a micro-LED array

Abstract Direct writing systems equipped with a confocal micro-light-emitting diode array can employ active illumination for alignment purposes. Based on the principles of single-pixel imaging, structured illumination can be used to obtain position information via compressive sensing. The positions of markers with certain spectral signatures can be extracted from the recorded hyperspectral data through spectral filtering, spectral fitting, or principal component analysis. Its application to direct writing is demonstrated by creating individual photolithography patterns aligned with different types of fluorophores on the same substrate.