%0 Book Section
%T MEGARA. Large pupil element tests and performance
publisher SPIE-Int. Soc. Optical  Engineering
%D 2016
%U 978-1-5106-0203-8
%@ https://hdl.handle.net/20.500.14352/19566
%X MEGARA is a third generation spectrograph for the Spanish 10.4m telescope (GTC) providing two observing modes: a large central Integral Field Unit (IFU), called the Large Compact Bundle (LCB), covering a FOV of 12.5 × 11.3 arcsec^(2) , and a Multi-Object Spectrograph (MOS) with a FOV of 3.5 × 3.5 arcmin^(2) . MEGARA will observe the whole visible range from 3650A to 10000A allowing different spectral resolutions (low, medium and high) with R = 6000, 11000 and 18000 respectively. The dispersive elements are placed at the spectrograph pupil position in the path of the collimated beam and they are composed of a set of volume phase hologram gratings (VPHs) sandwiched between two flat windows and coupled in addition to two prisms in the case of the medium- and high-resolution units. We will describe the tests and setups developed to check the requirements of all units, as well as the obtained performance at laboratory.
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