Improved High Collection Efficiency in Fluorescence Microscopy with a Weierstrass-Sphere Solid Immersion Lens

Abstract

We investigate improvements of the collection efficiency in fluorescence microscopy with a Weierstrass-sphere solid immersion lens (SIL). Using a Weierstrass-sphere SIL with refractive index n=1.845 and an objective lens with 0.55 numerical aperture, we demonstrate the high collection efficiency of fluorescence from 0.11-µm-diameter dye-doped microsphere bead samples, which is 21 times higher than that measured in conventional microscopy and is estimated to be 76%. Illumination uniformity and aberrations in Weierstrass-sphere SILs are also evaluated.