Optimal Design of Optics for Submillimeter Astronomy (Letters)

We have designed two- and three-element shaped reflecting telescopes which minimize diffraction losses and sidelobes for submillimeter radiometric and spectrometric application. New solutions for the near-field output of an off-axis paraboloid when illuminated with a beam of considerable power taper (20 dB) show the merit of using Gaussian illumination for which the feed telescope may be explicitly designed. Conventional long-focus Cassegrain telescopes can, by using a suitably positioned off-axis conic to give a condensed focal patch, be converted for submillimeter sky chopping.