Telescope mirrors of old basically came in one shape: they were round and fit nicely inside a tube. No longer. An emerging optics technology now allows these light-gathering devices to take almost any shape, potentially providing improved image quality over a larger field of view -- all in a smaller package.
Called freeform optics, this emerging mirror technology, brought about by advances in computer-controlled fabrication and testing, has triggered a sea change in optical engineering. Seeing the benefit of "potato chip-shape" or asymmetrical optics, NASA optical engineers at the Goddard Space Flight Center in Greenbelt, Maryland, have moved quickly to establish an expertise in this emerging technology.
"The use of freeform optics can significantly reduce the package size as well as improve the image quality," said Joseph Howard, who is working with Goddard engineer Garrett West to ultimately design, integrate, and test a two-mirror freeform optical telescope for imaging and spectroscopic applications.
http://www.eurekalert.org/pub_releases/2015-11/nsfc-owt110515.php
[Also Covered By]: PHYS.ORG
[Source]: NASA Goddard
(Score: 0) by Anonymous Coward on Friday November 06 2015, @07:43PM
Axi-symmetric would place the secondary reflector in the field of view, which in turn reduces the quality of the image (e.g. diffraction effects). An asymmetric design could put the secondary off axis more easily - consider a Herschelian reflector as an example (
http://www.telescope-optics.net/tilted2.htm/ [telescope-optics.net]