Single-pixel microscopy: principles, new sampling approaches and applications

Abstract

This thesis introduces the concept of single-pixel imaging (SPI) to optical microscopy, designing, implementing and evaluating SPI-based microscopes for use in situations where camera-based systems are ineffective due to spectral constraints, low photon counts and high costs. To this end, three key challenges are addressed: optical sectioning, lateral resolution and acquisition time. Structured-illumination microscopy (SIM) is employed to enhance optical sectioning by projecting high-spatial-frequency fringes and to improve resolution by combining super-resolution patterns with conventional ones used in SPI. Additionally, the work extends microscopy to computational optical scanning holography (COSH) with optical sectioning, enabling fast volumetric acquisitions and mitigating out-of-focus blur. Finally, the thesis proposes a sampling-pattern preselection algorithm guided by an analysis of sampling patterns within the constraints of the optical system. This reduces the number of required measurements and patterns for the sampling process.