125mm fused silica plane mirror

Product Description

Large Precision Fused Silica Plane Mirror – 125 mm Diameter × 24.5 mm Thick, Protected Aluminum First-Surface

This is an exceptional, large-diameter precision plane mirror crafted from high-purity fused silica, featuring a protected aluminum first-surface coating. With its substantial 24.5mm thickness, it delivers exceptional rigidity and wavefront stability, making it a professional-grade optic for demanding laser, metrology, and research applications—at a significant savings over new custom fabrication.

Key Specifications:

• Diameter: 125 mm (≈4.92 inches)

• Thickness: 24.5 mm (monolithic stability, minimizes distortion)

• Material: Fused Silica (UV-grade, low thermal expansion, high laser damage threshold)

• Surface Figure: Plano (λ/10 or better typical) – suitable as a reference flat

• Coating: Protected Aluminum (broadband ~95–98% reflectivity, visible to NIR)

• Clear Aperture: 117 mm (central area; holder marks outside this zone)

• Back & Edges: Finely ground for safety and mounting

Why This Mirror Is a Superior Value:

• Rare Size & Thickness: A 125mm diameter, 24.5mm thick fused silica mirror offers lab-grade stability rarely found on the surplus market.

• Reference-Grade Flatness: Suitable as a reference flat for interferometry, autocollimation, or testing other optics.

• High-Power Ready: Fused silica substrate and protected Al coating provide a high laser damage threshold for demanding beam steering applications.

Applications:

• Optical Metrology: Reference flat for interferometers, or for Foucault/knife-edge testing of telescope mirrors

• Laser Systems: Stable beam steering, folding, or periscope mirrors in UV-Vis-NIR setups

• Research & Instrumentation: Critical mirror in spectroscopy, imaging systems, or scientific instruments where thermal stability is paramount

• Advanced Hobbyist & Education: Perfect for serious amateur telescope makers, university optics labs, or laser enthusiasts