Laser damage comparisons of broad-bandwidth, high-reflection optical coatings containing TiO₂, Nb₂O₅, or Ta₂O₅ high-index layers

Journal Article · 21 September 2016 · Optical Engineering

DOI: https://doi.org/10.1117/1.OE.56.1.011018 · OSTI ID:1334376

Field, Ella Suzanne ^[1]; Bellum, John Curtis ^[1]; Kletecka, Damon E. ^[1]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

Broad bandwidth coatings allow angle of incidence flexibility and accommodate spectral shifts due to aging and water absorption. Higher refractive index materials in optical coatings, such as TiO₂, Nb₂O₅, and Ta₂O₅, can be used to achieve broader bandwidths compared to coatings that contain HfO₂ high index layers. We have identified the deposition settings that lead to the highest index, lowest absorption layers of TiO₂, Nb₂O₅, and Ta₂O₅, via e-beam evaporation using ion-assisted deposition. We paired these high index materials with SiO₂ as the low index material to create broad bandwidth high reflection coatings centered at 1054 nm for 45 deg angle of incidence and P polarization. Furthermore, high reflection bandwidths as large as 231 nm were realized. Laser damage tests of these coatings using the ISO 11254 and NIF-MEL protocols are presented, which revealed that the Ta₂O₅/SiO₂ coating exhibits the highest resistance to laser damage, at the expense of lower bandwidth compared to the TiO₂/SiO₂ and Nb₂O₅/SiO₂ coatings.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1334376
• Report Number(s): SAND--2016-8416J; 646957
• Journal Information: Optical Engineering, Journal Name: Optical Engineering Journal Issue: 1 Vol. 56; ISSN 0091-3286
• Publisher: SPIECopyright Statement
• Country of Publication: United States
• Language: English