OLIVA, ErnestoErnestoOLIVATOZZI, AndreaAndreaTOZZIFERRUZZI, DeboraDeboraFERRUZZIRIVA, MarcoMarcoRIVAGenoni, MatteoMatteoGenoniMarconi, AlessandroAlessandroMarconiMaiolino, R.R.MaiolinoORIGLIA, LiviaLiviaORIGLIA2020-10-232020-10-23201897815106195860277-786Xhttp://hdl.handle.net/20.500.12386/27967The first generation of ELT instruments will include an optical-infrared High Resolution Spectrograph, conventionally indicated as ELT-HIRES. This paper describes the optical design and overall architecture of the instrument whose main capabilities can be summarized as follows. - Fibers fed specrographs with resolving power R=100,000 (HR-modes), R=150,000 (UHR-modes) and R=20,000 (MR-modes). - Simultaneous wavelength coverage from 400 nm to 1800 nm; extendable to 300-2400 nm. - Spectrometers with fixed configurations and without moving optical parts. - Maximum size of entrance apertures ideal for seeing limited observations. - Many observing modes, including seeing-limited single-object spectroscopy, multi-objects medium resolution spectroscopy and IFU observations with different spatial scales, down to the diffraction limit of the ELT telescope. - Observing modes defined and selected in interfaces outside of the spectrographs. - Modular design compatible with a minimal baseline that can be subsequently expanded and upgraded.ELETTRONICOenConference paper10.1117/12.23099232-s2.0-85051169660000452664300220https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10702/2309923/ELT-HIRES-the-high-resolution-instrument-for-the-ELT/10.1117/12.2309923.full2018SPIE10702E..8OOFIS/05 - ASTRONOMIA E ASTROFISICA