Share Email Print

Proceedings Paper

Coronagraph mask tolerances for exo-Earth detection
Author(s): Oliver P. Lay; Joseph J. Green; Daniel J. Hoppe; Stuart B. Shaklan
Format Member Price Non-Member Price
PDF $17.00 $21.00

Paper Abstract

The direct detection at visible wavelengths of Earth-like planets around nearby stars requires starlight suppression by a factor of 1010 - 1011 at offsets of order 100 mas. It has been shown that perfect suppression is possible in principle, using a combination of a band-limited focal plane coronagraphic mask and a pupil plane Lyot stop. Errors in the transmission amplitude and phase of the mask degrade the performance. These errors can be corrected completely at a given wavelength and polarization using deformable mirrors (DMs) operating in the pupil plane of the system. Both the errors and correction have different chromatic dependences, however, and the DM correction becomes ineffective as the optical bandwidth is increased. The mask errors can be divided into 2 classes: (1) errors that are uncorrelated with the mask pattern, arising, for example, from the surface roughness of the mask substrate, and (2) errors that are correlated with the mask pattern. We present the results of analysis of random errors and simulate the effects of systematic errors using a specific example mask design. In both cases we find that the contrast required by TPF-C imposes very challenging demands on the design and fabrication of the masks. Several potential mitigation approaches are discussed.

Paper Details

Date Published: 31 August 2005
PDF: 14 pages
Proc. SPIE 5905, Techniques and Instrumentation for Detection of Exoplanets II, 59050I (31 August 2005); doi: 10.1117/12.618063
Show Author Affiliations
Oliver P. Lay, Jet Propulsion Lab. (United States)
Joseph J. Green, Jet Propulsion Lab. (United States)
Daniel J. Hoppe, Jet Propulsion Lab. (United States)
Stuart B. Shaklan, Jet Propulsion Lab. (United States)

Published in SPIE Proceedings Vol. 5905:
Techniques and Instrumentation for Detection of Exoplanets II
Daniel R. Coulter, Editor(s)

© SPIE. Terms of Use
Back to Top
Sign in to read the full article
Create a free SPIE account to get access to
premium articles and original research
Forgot your username?