Astronomical optics: Zonal aberration correction - Laboratory experiments and extrapolations to space- and ground-based observations
Abstract
The author describes the results of a laboratory experiment with a 143 mm diameter Cassegrainian telescope plagued by static irregular zonal aberrations with rotational symmetry and 620 nm peak to valley amplitude wavefront error. An adapted 16 mm useful diameter intrafocal corrector plate has been surfaced using a 2 μ-thickness photoresist coating on an optical substrate, ad-hoc non-uniform exposure via a two-axis computercontrolled scanning device and subsequent development and baking. The effect of losses by diffusion and absorption due to the corrector plate is small with respect to the increase of contrast due to the wavefront correction. Three extrapolations of this experiment are discussed: (1) How to use correctors in the UV range where the size of the Airy disk becomes smaller for a given aperture. (2) Correction of aberrations with no rotational symmetry. (3) Feasible correctors and relay optics adapted to large (4-8 m diameter) instruments have a 50 mm corrected field, well matched to modern image detectors.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- March 1987
- Bibcode:
- 1987A&A...175..345A
- Keywords:
-
- Aberration;
- Cassegrain Optics;
- Optical Correction Procedure;
- Telescopes;
- Error Correcting Devices;
- Image Contrast;
- Symmetry;
- Transmission Efficiency;
- Astronomy