RECENT DEVELOPMENTS IN THE APPLICATION OF THE FABRY-PEROT INTERFEROMETER TO SPACE RESEARCH
Résumé
For orbiting astronomical telescopes and rocket spectroscopy the great angular dispersion of the Fabry-Perot interferometer should permit easier guidance tolerance for a given spectral resolving power with the added profit of the physical compactness of an etalon spectrometer or spectrograph. Moreover the superiority in luminosity and illumination of the interferometer instruments would permit shorter exposures and greater time resolution. Work aimed at extending the spectral range of the interferometer for high resolution work on the solar Frauenhofer spectrum (3 000 Å-1 800 Å) from stabilized rockets is reviewed. The first problem of producing suitable semi-reflecting coatings for the region < 2 400 Å has now been solved by the development of magnesium fluoride overcoated aluminum films and the results obtained are illustrated with interferograms of λ 1 849 of Hg I and transmission curves of interference filters for the range 1 700 Å to 2 400 Å. The development of an optically contacted air gap Fabry-Perot interferometer for rocket spectroscopy is also described. A recorded fringe finesse of 30 for a 2 cm aperture has been obtained at λ 5 461 with this instrument, and the adjustment remains constant with time. Finally, two rocket experiments to study the resonance lines of Mg II at 2 795 and 2 802 Å are described. The first experiment will comprise a Fabry-Perot interferometer crossed with an echelle spectrograph to give a spectral resolution in the fringes of about 0.03 Å at 2 800 Å with a solar spatial resolution of 10 seconds of arc radially. The second experiment will employ a scanning Fabry-Perot interferometer, also crossed with an echelle, with photoelectric detection.
Domaines
Articles anciens
Origine : Accord explicite pour ce dépôt