aat Acta Astrophys. Tau. Acta Astrophysica Taurica 2712-925X Kiselev Nikolai Nikolaevich, Mosсow, settlement Moskovskii, Tat'yanin Park Str., 12, Moscow, Russia. RU 119 Research articles Electro-optic modulators for solar magnetic field observations at ISTP Tokareva Ljubov' Skomorovsky Valery Kushtal Galina Institute of Solar-Terrestrial Physics SB RAS, Irkutsk 664033, Russia Institute of Solar-Terrestrial Physics SB RAS, Irkutsk 664033, Russia Institute of Solar-Terrestrial Physics SB RAS, Irkutsk 664033, Russia 25 12 2025 6 4 24 28 24 12 2025 Copyright (c) 2026 Tokareva L., Skomorovsky V., Kushtal G. 2026 Ljubov' Tokareva, Valery Skomorovsky, Galina Kushtal The metadata for this submission is licensed under a Creative Commons Attribution 4.0 International License. Copyright and publishing rights for texts published in Acta Astrophysica Taurica is retained by the authors, with first publication rights granted to the journal.Texts are free to use with proper attribution and link to the licensing (Creative Commons Attribution 4.0 International).

The paper describes the main stages in developing electro-optic modulators (EOMs) based on the KDP group crystals for solar magnetographs at ISTP SB RAS. The optical-physical characteristics of modulators are studied. The reasons for EOM failure are analyzed, and ways to eliminate them are proposed. The EOM designs have been developed for different types of control voltages.

solar magnetograph polarization Pockels effect KDP crystal Borodin A.N., Petrov A.S., Domyshev G.N., et al. 2003. Electro-optic phase modulator. Patent RU 2248601 G02F 1/03. (In Russ.) Demidov M.L., Grigoriev V.M., Retyunsky L.B., et al., 2018. Izv. Krymsk. Astrofiz. Observ., vol. 114, no. 2, pp. 21–26. (In Russ.) Grigoriev V.M., Kobanov N.I. 1980. Research on geomagnetism, aeronomy and solar physics, vol. 52, pp. 155–176. (In Russ.) Kuznetsov D.A., Kuklin G.V., Stepanov V.E. 1966. Results of observations and research during the MGSS period, vol. 1, pp. 80–87. (In Russ.) Markov V.S., Domyshev G.N., Skomorovsky V.I., 1988. Research on geomagnetism, aeronomy and solar physics, vol. 83, pp. 141–149. (In Russ.) Nikulin N.S., Severny A.V., Stepanov V.E., 1958. Izv. Krymsk. Astrofiz. Observ., vol. 19, pp. 3–20. (In Russ.) Proshin V.A., Skomorovsky V.I., Kushtal G.I., et al., 2013. Electro-optic modulator of polarized radiation. Patent RU(11)130 094(13)U1. (In Russ.) Stepanov V.E., Grigoriev V.M., Kobanov N.I., 1975. Research on geomagnetism, aeronomy and solar physics, vol. 37. pp. 147–153. (In Russ.)