Broadband aberration-corrected snapshot spectrometer with a toroidal slicer mirror

We demonstrate a broadband aberration-corrected snapshot spectrometer by developing a toroidal slicer mirror as the focusing mirror. A collimating slicer mirror and an integrated grating divide the entire wavelength range into several windows. The toroidal sub-mirrors of the focusing mirror compensate for the coma and correct the astigmatism at different windows to compress the spectral spots over the waveband. From 200 to 1000 nm, the RMS spot radii are less than 30 μm and the spectral resolution at 600 nm is 151.8 pm. The optics have a small volume of 11 cm×11 cm×1.5 cm by employing a folded structure.