Improved spatial resolution using focal modulation microscopy with a Tai Chi aperture

Abstract

Focal modulation microscopy (FMM) has gained significant interest in biological imaging. However, the spatial resolution and penetration depth limit the imaging quality of FMM due to the strong scattering background. Here, we introduce FMM with a Tai Chi aperture (TCFMM) based on diffraction theory to improve the spatial resolution. The results show that the transverse resolution is improved by 61.60% and 41.37% in two orthogonal directions, and the axial resolution is improved by 29.67%, compared with confocal microscopy (CM). The signal background ratio (SBR) of TCFMM is increased by 23.26% compared with CM and remains nearly the same compared with FMM using D-shape apertures (DFMM). These improvements in spatial resolution and SBR indicate that TCFMM has potential in deep tissue imaging.