Design strategy for a dual-wedge prism imaging spectrometer in spectroscopic nanoscopy.

This article focuses on the design principles and optimization of a dual-wedge prism (DWP) imaging spectrometer for spectroscopic single-molecule localization microscopy (sSMLM), a technique that combines spatial and spectral imaging at nanoscale resolution. The DWP spectrometer, a compact monolithic optical component integrating a beam splitter, right-angle prism, and two wedge prisms, improves localization precision and system reliability compared to traditional grating-based spectrometers by enhancing photon efficiency and reducing optical complexity. The authors present a theoretical framework and practical workflow for selecting materials, wedge angles, and dimensions to achieve desired spectral dispersion (SD) and axial separation for three-dimensional biplane imaging, supported by simulations and analytical models estimating spatial and spectral localization precision under various conditions. While the DWP design facilitates straightforward 3D sSMLM integration and multi-color imaging with improved performance, limitations include reduced flexibility for very high SD values and challenges in switching between 2D and 3D imaging modes without system modifications. This work aims to guide researchers in optimizing DWP spectrometers for enhanced functional super-resolution imaging in biological and chemical applications.