Realization of a compact cross-grating spectrometer and validating experimental tests.

Echelle inspired cross-grating spectrometers offer the potential to bridge the gap between classical high-end echelle spectrometers and curved-grating single-element instruments. In particular, the cross-grating approach offers the possibility to simultaneously achieve a high spectral resolution and a wide accessible spectral range in compact dimensions and without moving parts. We report on the complete realization and implementation details of an all-reflective cross-grating spectrometer based on a modified Czerny-Turner configuration including a folded beam path and a toric-convex mirror for aberration compensation. The applicability of the cross-grating spectrometer is demonstrated by test measurements including the recording of the spectra of different plant leaves. For the cross-grating spectrometer, with an accessible wavelength range between 330 and 1100 nm, a spectral resolution of 0.6 nm at 589 nm was achieved.