Computer Science – Performance
Scientific paper
Jan 2009
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2009aas...21345110t&link_type=abstract
American Astronomical Society, AAS Meeting #213, #451.10; Bulletin of the American Astronomical Society, Vol. 41, p.346
Computer Science
Performance
Scientific paper
Direct imaging of extra-solar planets is important for determining the properties of individual planets and to study multi-planet systems. Obtaining spectra of extra-solar planets enables us to constrain the composition of planetary atmospheres and surfaces, their climates, their evolution, and their rotation periods. The Lyot coronagraph is one of the important techniques to acquire these spectra. In its simplest design it consists of a telescope, an occulter mask in the first focal plane, a Lyot stop in the following pupil plane, and the detector in the final focal plane. The goal of ongoing research is to achieve the best possible performance from a Lyot coronagraph. Among the study objects is the occulter mask. We are studying a new manufacturing method to overcome the main problems of occulter masks: undesired chromatic effects and intolerable phase distortions. Our method utilizes substrates covered with highly absorbing dye mixtures (optical density of 1 per micron) and focused ion beam (FIB) milling of the mask profiles into these dyes. By combining several dyes with pre-determined mixing ratios, we are able to control the chromaticity of the mask from decreasing to flat to increasing absorptivity with wavelengths. Phase effects occur in these masks only at the transition from the dye to its surrounding medium. The idea is to control these phase effects by embedding the masks in clear, phase-matching glass. This poster will present the progress we made in finding and characterizing suitable materials and the results of first optical tests of FIB machined mask-like structures in dye-doped PMMA. This work was supported by NASA through grant NNG04GC57G and NSF through grant AST-0750222, through SAO IR&D funding and by Harvard University. Central facilities were provided by Harvard's Center for Nanoscale Systems.
Aziz Michael J.
Raja S.
Tolls Volker
No associations
LandOfFree
Fabrication of Soft-Edged Occulting Masks for Coronagraphs does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Fabrication of Soft-Edged Occulting Masks for Coronagraphs, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fabrication of Soft-Edged Occulting Masks for Coronagraphs will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1705100