2018/05/23 by Eduard Muslimov, Marc Ferrari, Muslimov, Eduard +17 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #Optical Coatings and Gratings #Optical Polarization and Ellipsometry #Photocathodes and Microchannel Plates #astro-ph.IM
paper · pdf · doi:10.48550/arxiv.1805.09073
arxiv created 2018/05/23 · arxiv updated 2018/05/24
In the present paper we demonstrate the approach to use a holographic grating on a freeform surface for advanced spectrographs design. On the example POLLUX spectropolarimeter medium-UV channel we chow that such a grating can operate as a cross-disperser and a camera mirror at the same time. It provides the image quality high enough to reach the spectral resolving power of 126 359-133 106 between 11.5 and 195 nm, which is higher than the requirement. Also we show a possibility to use a similar element working in transmission to build an unobscured double-Schmidt spectrograph. The spectral resolving power reaches 2750 for a long slit. It is also shown that the parameters of both the gratings are feasible with the current technologies.