Two-photon absorption measurements of deep UV transmissible materials at 213 nm

S Patankar; S T Yang; J D Moody; G F Swadling; A C Erlandson; A J Bayramian; D Barker; P Datte; R L Acree; B Pepmeier; R E Madden; M R Borden; J S Ross

doi:10.1364/AO.56.008309

Two-photon absorption measurements of deep UV transmissible materials at 213 nm

Appl Opt. 2017 Oct 20;56(30):8309-8312. doi: 10.1364/AO.56.008309.

Authors

S Patankar, S T Yang, J D Moody, G F Swadling, A C Erlandson, A J Bayramian, D Barker, P Datte, R L Acree, B Pepmeier, R E Madden, M R Borden, J S Ross

PMID: 29091606
DOI: 10.1364/AO.56.008309

Abstract

We report on two-photon absorption measurements at 213 nm of deep UV transmissible media, including LiF, MgF₂, CaF₂, BaF₂, sapphire (Al₂O₃), and high-purity grades of fused-silica (SiO₂). A high-stability 24 ps Nd:YAG laser operating at the 5th harmonic (213 nm) was used to generate a high-intensity, long-Rayleigh-length Gaussian focus inside the samples. The measurements of the fluoride crystals and sapphire indicate two-photon absorption coefficients between 0.004 and 0.82 cm/GW. We find that different grades of fused silica performed near identically for two-photon absorption; however, there are differences in linear losses associated with purity. A low two-photon absorption cross section is measured for MgF₂, making it an ideal material for the propagation of high-intensity deep UV lasers.