Vintage 1989 Fused Silica Laser Optical Windows – 100mm – LOT OF 2

Rare matched pair of genuine 1980s fused silica (fused quartz) optical windows—perfect for laser history enthusiasts or recoating projects! Both pieces are from the same era with identical specs and markings.

Specifications (Each):

• Diameter: 100 mm (~4 inches)

• Thickness: 12 mm (substantial and heavy)

• Material: High-purity fused silica (excellent broad-spectrum transmission, high damage threshold)

• Surfaces: Precision polished plano-plano with beveled edges

• Original coating: Dual-side multilayer dielectric (golden-yellow reflection, likely BBAR for visible/NIR)

Originally used in high-power laser systems (e.g., Nd:YAG, excimer, or CO2) as output couplers, debris shields, viewports, or beam samplers—ideal for applications needing thermal stability and UV-to-IR transparency.

Condition Notes: Substrates are in great shape—crystal clear, no scratches/chips. However, the original coatings show typical age-related degradation (35+ years old): patchy tint, blotches, edge delamination/flaking (visible in photos). This causes scatter/reduced performance in critical optics but doesn’t affect the core material. Sold as-is for surplus, collectible, educational (coating failure demo), or recoating use. Not for high-precision without refurb.

Great for:

• Matched spares in laser builds

• Recoating blanks (new equivalents cost $600–900 for a pair uncoated)

• Vintage optics collection or unique desk art/paperweights