Lithium niobate for next-generation instruments of Galileo Solar Space Telescope (GSST/INPE)

• Grant number: 21/13309-6
• Support Opportunities: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): April 01, 2022
• Effective date (End): March 31, 2024
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Astronomical Instrumentation
• Principal Investigator: Luis Eduardo Antunes Vieira
• Grantee: Franciele Carlesso
• Host Institution: Instituto Nacional de Pesquisas Espaciais (INPE). Ministério da Ciência, Tecnologia e Inovações (Brasil). São José dos Campos , SP, Brazil

Abstract

The Galileo Solar Space Telescope (GSST) project aims to observe the evolution of solar magnetic structures and their impact on the Geospace. Lithium niobate crystal (LiNbO3 or LN) has excellent properties for application in two GSST instruments. The observations from the spectropolarimeter are based on the polarization state of light at different wavelengths of a spectral line sensitive to the Zeeman effect. However, the Fabry-Perot Etalon scan response time is not fast enough for some solar phenomena. The GSST group is developing a narrowband imager using volumetric diffraction gratings based on photorefractive materials such as Fe:LN. GSST group is developing a volumetric holographic grating narrowband imager based on photorefractive materials such as Fe:LN. In addition, an absolute radiometer, based on the principle of electrical substitution, is under development to monitor total solar irradiance. Optical integrated circuits are potentially an alternative to compact radiometers based on LN functionality. The device performance depends on the crystal quality. The project aims tailored optimized crystals for the TSI radiometer and spectropolarimeter applications. We intend to start the study by the growth of LN single-crystal fibers by the micro-pulling down method to establish the optimal experimental conditions for the subsequent growth of single volumetric crystals of good optical and structural quality using the Czochralski technique. Conceive the radiometer sensor architecture and define requirements for its functional parts. This research will greatly contribute, within the GSST project, to overcome the technological limitations currently addressed by the scientific community in solar observations. (AU)