We discuss the possibility of improving the optical efficiency of ELT instruments by reducing the number of optical surfaces with highly aspheric optics generated by deformable mirrors (DMs). Preliminary analysis shows that a 2 aspheric mirror design could in principle replace a traditional optical design with a complex series of ~ 10 lenses, providing a potential gain in efficiency of ~ 20% as well as a significant gain in compactness. New OH suppression systems based on technologies from the photonics world become available that may ultimately allow to reduce the near IR sky brightness by 2 to 4 magnitudes, depending on wavelength. The potential performance of an ELT with OH suppression is similar in imaging and significantly higher in spectroscopy than JWST.

Date Published: 29 June 2006
PDF: 9 pages
Proc. SPIE 6269, Ground-based and Airborne Instrumentation for Astronomy, 62691U (29 June 2006); doi: 10.1117/12.671619

Published in SPIE Proceedings Vol. 6269:
Ground-based and Airborne Instrumentation for Astronomy
Ian S. McLean; Masanori Iye, Editor(s)