Cryogenic lens designers of large optics need to know what materials are available and in what size. As of 19-Sept-2019 I’ve identified the following materials:
Up to 200 mm in diameter with good (> 90% in 10 mm samples) throughput up to 2.45 µm in wavelength are:
- ZnSe
- E-SF03
- Calcium Fluoride (CaF2)
- Infrasil (Heraeus fused silica)
- BaF2
- S-FTM16
- S-PHM52
- S-TIM28
- S-TIM1
Up to 100 mm in diameter include:
- S-NPH2
- S-TIH14
- S-TIH1
Those interested can grab glass catalogs from my drive. Note, these catalogs do not contain the cryogenic index of refractions. Feel free to contact me with any questions or comments.
Nick Konidaris 