Publication: MEGARA Spectrograph Optics
Full text at PDC
Sánchez Blanco, E.
García Vargas, M. L.
Gil de Paz, Armando
Sánchez, F. M.
Vílchez, J. M.
Advisors (or tutors)
SPIE-Int Soc Optical Engineering
MEGARA is the next optical Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) for Gran Telescopio Canarias. The instrument offers two IFUs plus a Multi-Object Spectroscopy (MOS) mode: a large compact bundle covering 12.5 arcsec x 11.3 arcsec on sky with 100 μm fiber-core; a small compact bundle, of 8.5 arcsec x 6.7 arcsec with 70 μm fiber-core and a fiber MOS positioner that allows to place up to 100 mini-bundles, 7 fibers each, with 100 μm fiber-core, within a 3.5 arcmin x 3.5 arcmin field of view, around the two IFUs. The fibers, organized in bundles, end in the pseudo-slit plate, which will be placed at the entrance focal plane of the MEGARA spectrograph. The large IFU and MOS modes will provide intermediate to high spectral resolutions, R=6800-17000. The small IFU mode will provide R=8000-20000. All these resolutions are possible thanks to a spectrograph design based in the used of volume phase holographic gratings in combination with prisms to keep fixed the collimator and camera angle. The MEGARA optics is composed by a total of 53 large optical elements per spectrograph: the field lens, the collimator and the camera lenses plus the complete set of pupil elements including holograms, windows and prisms. INAOE, a partner of the GTC and a partner of MEGARA consortium, is responsible of the optics manufacturing and tests. INAOE will carry out this project working in an alliance with CIO. This paper summarizes the status of MEGARA spectrograph optics at the Preliminary Design Review, held on March 2012.
© 2012 SPIE. Conference on Ground-Based and Airborne Telescopes IV (2012. Amsterdam, Netherlands).
 A. Gil de Paz, E. Carrasco, J. Gallego, M. Sánchez, J.M. Vílchez, M.L. García Vargas et al. "MEGARA: the future optical IFU and multi-object spectrograph for the 10.4m GTC telescope" These Proceedings (2012).  Carrasco, Esperanza; Sánchez Blanco, Ernesto; García Vargas, María Luisa; Gil de Paz, Armando; Gallego, Jesús; Páez, Gonzalo; Zamorano, Jaime; Castro, Jorge. "Optical Design for MEGARA: a multi-object spectrograph for the GTC" 22nd Congress of the International Commission for Optics: Light for the Development of the World. Edited by Rodríguez Vera, Ramón; Díaz Uribe, Rufino. Proceedings of the SPIE, Volume 8011, pp. 80112D-80112D-10 (2011).  Sánchez Blanco, E.; García Vargas, M.; Maldonado, M.; Gallego, J.; Gil de Paz, A.; Carrasco, E.; Pérez, A.; Martínez Delgado, I.; Zamorano, J. "Sliced-pupil grating: a novel concept for increasing spectral resolution" 22nd Congress of the International Commission for Optics: Light for the Development of the World. Edited by Rodríguez Vera, Ramón; Díaz Uribe, Rufino. Proceedings of the SPIE, Volume 8011, pp. 80111I-80111I-10 (2011).