Designing chromatic optical retarder stacks for segmented next‐generation easySTED phase plates. (19th October 2022)

• Record Type: Journal Article
• Authors: Engelhardt, Johann; Ellerhoff, Beatrice; Gürth, Clara‐Marie; Sahl, Steffen J.; Hell, Stefan W.
• Is Part Of: Journal of microscopy. Volume 288:Part 2(2022)
• Page Start: 142
• Page End: 150
• Publication Date: 2022-10-19
• Subjects: fluorescence nanoscopy -- intensity minimum -- phase plate -- polarisation -- RESOLFT -- STED; Microscopy -- Periodicals; 502.82
• DOI: 10.1111/jmi.13143
• Languages: English
• ISSNs: 0022-2720

Abstract

Abstract: Fluorescence nanoscopy methods based on the RESOLFT principle, such as beam‐scanning STED nanoscopy, require the co‐alignment of optical beams for molecular state (on/off) switching and fluorescence excitation. The complexity and stability of the beam alignment can be drastically simplified and improved by using a single‐mode fibre as the sole light source for all required laser beams. This in turn then requires a chromatic optical element for shaping the off‐switching beam into a focal‐plane donut while simultaneously leaving the focal intensity distributions at other wavelengths shaped as regular focal spots. Here we describe novel designs of such so‐called 'easySTED phase plates' and provide a rationale how to find the desired spectral signature for combinations of multiple wavelengths.