Translator Disclaimer
24 December 2003 Use of the LIGA process for the production of pyramid wavefront sensors for adaptive optics in astronomy
Author Affiliations +
Abstract
Nowadays many groups in the world are developing adaptive optics (AO) systems for the real time correction of the aberrations introduced by the turbolence of the atmosphere in the field of view of the astronomical telescopes. The Shack-Hartmann wavefront sensor has been often used for the detection of the optical aberrations but over the past few years an alternative wavefront sensor with pyramidic shape has being developed. The properties of this sensor have been extensively investigated both theoretically and experimentally (for example in the AO module of the Italian “Telescopio Nazionale Galileo”). Important features of this pyramidal sensor are that it offers the advantage of either variable gain against the wavefront deformation and tunable sampling of the telescope pupil. These features translate into a considerable gain in the limiting magnitude of the reference star when compared to the classical Shack-Hartmann sensor. The manufacturing of single pyramid prototypes has been initially accomplished using the classical figuring and polishing technique, a time consuming procedure. Since the multi-conjugated adaptive optics (MCAO) that are under study, foresee the use of a large number of identical pyramids, it has been investigated and developed an alternative method for the mass production of this optical component. Using a lithography-dedicated beamline already operating at the ELETTRA Synchrotron in Trieste, a manufacturing technique has been implemented that uses a process named LIGA [Lithography, electroplating (German: Galvanik) and molding (German: Abformung)]. With this method is it possible to create a master pyramid made of a polymeric material and having the characteristics requested. The master is then used to create a metallic mold by means of electroforming. In the end the mold is used for the molding of a number of identical pyramids made in a suitable amorphous optical polymer, using the technique of the hot embossing. This technique produce identical copies of the master pyramid, a desirable feature for the MCAO systems, and once the mold has been manufactured, permit a very fast production of large numbers of identical pyramids. In this paper we present the results obtained with this manufacturing process.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Mauro Ghigo, Emiliano Diolaiti, Frederic Perennes, and Roberto Ragazzoni "Use of the LIGA process for the production of pyramid wavefront sensors for adaptive optics in astronomy", Proc. SPIE 5169, Astronomical Adaptive Optics Systems and Applications, (24 December 2003); https://doi.org/10.1117/12.506100
PROCEEDINGS
7 PAGES


SHARE
Advertisement
Advertisement
RELATED CONTENT

Advances in IR technology at Paris Observatory
Proceedings of SPIE (October 31 1990)
Status of the VLT Nasmyth adaptive optics system (NAOS)
Proceedings of SPIE (July 06 2000)
Lessons learned from the development of the XMM optics
Proceedings of SPIE (August 26 1999)
PIGS on sky - dream or reality?
Proceedings of SPIE (July 06 2004)

Back to Top