Laser Research Optics sapphire windows come in 1 and 2 in. sizes

Sapphire windows for 1064 nm industrial cutting fiber lasers from 4 kW and above are highly durable replacements for debris shields. They have Moh 9 hardness and come in 1 and 2 in. sizes, with 10^-5 scratch dig finishes, 1/4-wave flatness, and AR coatings. Transmission is >99.5% at 1.07 μm and >90% at 650–670 nm.
Laser Research Optics
Providence, RI
www.laserresearch.net