Laboratory testing of the Ingot WFS

Simone Di Filippo; Davide Greggio; Maria Bergomi; Kalyan Kumar Radhakrishnan Santhakumari; Elisa Portaluri; Carmelo Arcidiacono; Valentina Viotto; Roberto Ragazzoni; Marco Dima; Luca Marafatto; Jacopo Farinato; Demetrio Magrin

arXiv · 2209.12921

Laboratory testing of the Ingot WFS

Simone Di Filippo·Davide Greggio·Maria Bergomi·Kalyan Kumar Radhakrishnan Santhakumari·Elisa Portaluri·Carmelo Arcidiacono·Valentina Viotto·Roberto Ragazzoni·Marco Dima·Luca Marafatto·Jacopo Farinato·Demetrio Magrin

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Abstract

The ingot WFS is a new kind of wavefront sensor specifically designed to deal with the elongation of LGS reference sources on ELT-class telescopes. Like the pyramid, it belongs to the family of pupil plane wavefront sensors and can be considered as a generalization of the pyramid WFS for extended, three-dimensional elongated sources. The current design uses a simple, reflective roof-shaped prism to split the light into three pupils that are used to retrieve the wavefront shape. A test-bench has been realized at the INAF-Padova laboratories to test the alignment and functioning of the ingot. The bench is equipped with a deformable lens, conjugated to the pupil plane, able to apply low-order aberrations and with a hexapod for the precise alignment of the ingot prism. In this work we present a robust and fully automated Python-code alignment procedure, which is able, by using the optical feedback from the I-WFS, to adjust its 6-degrees of freedom. Moreover, we report on the tests conducted with the deformable lens to characterize the ingot WFS response to low-order aberrations in terms of sensitivity and linearity. The results are used as a comparison for simulations to validate the ray-tracing modeling approach with the future goal of optimizing the procedure adopted for signal calculation and phase retrieval.

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Simone Di Filippo, Davide Greggio, Maria Bergomi, Kalyan Kumar Radhakrishnan Santhakumari, Elisa Portaluri, Carmelo Arcidiacono, Valentina Viotto, Roberto Ragazzoni, Marco Dima, Luca Marafatto, Jacopo Farinato, Demetrio Magrin. 2022-09-26. Laboratory testing of the Ingot WFS. https://arxiv.org/abs/2209.12921

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