Materion witness samples aluminum gold fused silica SET OF 4

Product Description

Matched Set of Four Rare Precision Mirror Witness Samples – Bare Aluminum & Gold Coatings on Fused Silica (US Defense Laboratory WFOV Telescope Project)

This is a unique, complete matched set of four witness samples originally coated by Materion Barr Precision Optics & Thin Film Coatings for a U.S. Defense Laboratory Wide Field of View (WFOV) Telescope Assembly. These 1.5-inch diameter, 1.5mm thick fused silica disks were co-deposited alongside the actual production mirrors (L3 and L4 elements) as quality-control and archival records. The set includes two bare aluminum coatings and two bare gold coatings, providing insight into a multi-spectral telescope design optimized for visible/NIR and IR performance.

Key Specifications:

• Quantity & Coating:

  • 2x Bare Aluminum (Al) – 92–95% reflectivity, visible to near-IR (~400–800 nm)

  • 2x Bare Gold (Au) – 98% reflectivity, near-IR to far-IR (~800 nm–20 µm+)

• Substrate: High-purity fused silica (SiO₂) – optically polished (λ/10 flatness or better)

• Dimensions: 1.5″ (38.1 mm) diameter × 1.5 mm thickness

• Provenance: Co-deposited with L3/L4 telescope mirror elements for a U.S. defense WFOV program

• Condition: Pristine, new, untarnished – stored in original protective cases

Why This Set Is Exceptional:

• Defense Program Provenance: Directly linked to a sophisticated multi-spectral surveillance telescope project.

• Dual-Coating Insight: Provides a tangible comparison between visible/NIR-optimized aluminum and IR-optimized gold coatings.

• Collector & Research Value: As witness samples, they represent a “slice” of the original coating run, offering historical and technical significance.

Applications:

• Amateur Astronomy / Telescope Building: High-quality folding mirrors, secondaries, or custom spectrograph optics; aluminum for visual, gold for IR projects.

• Scientific & Educational Demos: Teach coating performance, reflectivity, and multi-spectral design principles.

• Professional R&D: Reference samples for laser systems, metrology, remote sensing, or calibration (bare coatings offer peak native performance).

• Historical Collecting: Documented artifacts from a U.S. defense advanced optics program.