Wideband aberration-corrected spectrometer using a single toroidal grating: theory and prototype

This work introduces a wideband aberration-corrected high-resolution (WACHR) spectrometer. The design replaces the conventional collimating mirror and planar grating in the Czerny-Turner configuration with a toroidal diffraction grating. Theoretical modeling and optical simulations demonstrate that this configuration simultaneously suppresses astigmatism and wavelength-dependent coma across a broad spectral range. Compared with traditional designs, the proposed spectrometer exhibits superior imaging performance and higher spectral resolution, achieving 0.51-0.68 nm over 400-800 nm. A prototype was fabricated and experimentally validated, and the results confirm the theoretical predictions. These findings highlight the potential of the WACHR spectrometer for compact and high-precision spectral imaging applications.