Determination of the extinction coefficients of CR-39, MR-8, and MR-10 organic glasses in the near-ultraviolet to visible region

• Published in: Optical materials 2024-04, Vol.150, p.115250, Article 115250
• Main Authors: Gambaudo, Noémie, Twardowski, Patrice, Pauly, Matthias, Gérard, Philippe, Jagu, Romain, Flury, Manuel
• Format: Article
• Language: English
• Subjects: Engineering Sciences; Extinction coefficient; Optics; Organic glasses; Photonic; Reflectance; Refractive index; Thick slab materials; Transmittance
• ISSN: 0925-3467; 1873-1252
• DOI: 10.1016/j.optmat.2024.115250

The extinction coefficients of three commercial organic glasses referenced CR-39, MR-8 and MR-10 were determined from reflectance and transmittance spectra in the near-UV to visible region, using two different approaches. The first approach consists in the optimization of the extinction coefficient to fit the calculated transmittance to the optical measurements with a UV–Visible spectrometer. The second approach uses a simplified analytical expression of the extinction coefficient as a function of transmittance proposed in an article by S. Nemoto. The two calculation methods are compared and discussed. A table of complex refractive indices (including the determined extinction coefficients) is provided in the appendix, for open use. •Two methods are used to determine the extinction coefficient of organic glasses (CR-39, MR-8 and MR-10).•The reflectance is computed and compared with the measurements to confirm our results.•The influence of the error in the real part of the refractive index on the extinction coefficient is studied.•Precise complex refractive indices values of CR-39, MR-8 and MR-10 are provided in the appendix.