Bibcode
Insaustia, M.; Garzón, F.; Mas-Abellán, P.; Madrigal, R.; Fimia, A.
Bibliographical reference
Proceedings of the SPIE, Volume 10233, id. 102331C 8 pp. (2017).
Advertised on:
5
2017
Citations
0
Refereed citations
0
Description
Silver halide sensitized gelatin (SHSG) processes are interesting
because they combine the spectral and energetic sensitivity of a
photographic emulsions with good optical quality and high diffraction
efficiency of dichromate gelatin (DCG). Previous papers had been
demonstrated that it is possible to obtain diffraction efficiencies near
to 90% with Agfa- Gevaert plates and Colour Holographic plates in SHSG
transmission gratings. In this communication, we report on the
performances measured at room temperature and in cryogenic conditions of
a set of volume phase holographic gratings(VPHGs) manufactured with SHSG
process aimed at their use in astronomical instrumentations. Two set of
diffraction gratings has been manufactured using different processing.
The first with SHSG process and the second with typical bleached process
(developed with AAC and bleached in R-10). In both cases the plate was
BB640, ultrafine grain emulsions with a nominal thickness of 9 μm.
The recording was performed with asymmetric geometry a 30° degrees
between the light beams of wavelength 632.8 nm (He-Ne laser), which give
a raise a spectral frequency of 800 l/m. The exposure was between 46 to
2048 μJ/cm2. The results give us information about Bragg
plane modification and reduction of diffraction efficiency when we
introduced the VPHG to 77° K. In the case of SHSG process the final
diffraction efficiency after cryogenic temperature are better at some
exposure energy than previous measurements at room temperature. This
experimental result give us possibilities to applied SHSG process in
Astrophysics applications.