Solar-Terrestrial Physics Solar-Terrestrial Physics Solar-Terrestrial Physics 2500-0535 45905 10.12737/stp-81202209 Results of current research Results of current research Results of current research Iceland spar and birefringent filter (BF) development Iceland spar and birefringent filter (BF) development https://orcid.org/0000-0002-4697-0171 Скоморовский Валерий Иосифович Skomorovsky Valery Iosifovich skoal@iszf.irk.ru

доктор физико-математических наук;

doctor of physical and mathematical sciences;

 https://orcid.org/0000-0002-5809-1705 Кушталь Галина Ивановна Kushtal Galina Ivanovna kushtal@iszf.irk.ru

кандидат физико-математических наук;

candidate of physical and mathematical sciences;

 Токарева (Лоптева) Любовь Сергеевна Tokareva (Lopteva) Lyubov Sergeevna lopteva@iszf.irk.ru Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar Terrestrial Physics SB RAS Irkutsk Russian Federation 25 03 2022 25 03 2022 8 1 69 84 16 09 2021 18 11 2021 https://zh-szf.ru/en/nauka/article/45905/view

Birefringent crystals for BF are required to provide the necessary linear aperture, wavefront quality, and filter transmission in a given spectral region. Based on the review of foreign and domestic BF developments, the difficulties in using crystals from known deposits are examined. The Institute of Solar-Terrestrial Physics has developed BFs with extreme characteristics, using an innovative method for enriching crystals from East Siberian deposits and new methods for optical treatment and control of BF elements. We present the characteristics of the filters. Further progress in the creation of BFs in our country depends on the availability of necessary synthetic crystals and natural crystal of Iceland spar, which turned out to be a difficult fate in Russia.

Birefringent crystals for BF are required to provide the necessary linear aperture, wavefront quality, and filter transmission in a given spectral region. Based on the review of foreign and domestic BF developments, the difficulties in using crystals from known deposits are examined. The Institute of Solar-Terrestrial Physics has developed BFs with extreme characteristics, using an innovative method for enriching crystals from East Siberian deposits and new methods for optical treatment and control of BF elements. We present the characteristics of the filters. Further progress in the creation of BFs in our country depends on the availability of necessary synthetic crystals and natural crystal of Iceland spar, which turned out to be a difficult fate in Russia.

 birefringent filter Iceland spar crystal morphology optical treatment solar observations birefringent filter Iceland spar crystal morphology optical treatment solar observations The work was performed with budgetary funding of Basic Research program II.16 The work was performed with budgetary funding of Basic Research program II.16

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