2026-06-29T16:48:31Zhttps://docta.ucm.es/rest/oai/request

oai:docta.ucm.es:20.500.14352/186992024-09-10T18:21:18Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Ortiz, R. author Carrasco, E. author Paez, G. author Pompa, O. author Sánchez Blanco, E. author Gil De Paz, Armando author Gallego Maestro, Jesús author Iglesias Paramo, J. author 2018 MEGARA is the new integral field unit (IFU) and multi-object (MOS) spectrograph successfully commissioned at Gran Telescopio Canarias, in August 2017. MEGARA provides spectral resolutions R (fwhm) similar to 6000, 12000 and 20000, via volume phase holographic gratings, at very high efficiency in both IFU and MOS modes. In the case of MEGARA main optics and pupil elements optics, the surfaces in contact with air have an anti-reflective (AR) coatings to minimize the Fresnel losses at the interface glass-air. In this work we present the designs and calculation of the total throughput of the optical system based in the transmission measurements of the AR coated witness samples. The results reflect the benefits of having implemented customized AR coatings for the mean angle of incidence on each surface as the measured throughput was better than the requirements. We analyze the effects of the pupil elements AR coatings for each spectral configuration. 0277-786X 10.1117/12.2313976 https://hdl.handle.net/20.500.14352/18699 http://dx.doi.org/10.1117/12.2313976 https://www.spiedigitallibrary.org/ MEGARA anti-reflective coatings: theoretical and observed throughput estimations