254mm Dia. λ/20 Fused Silica Optical Flat

Product Details Sizes Ranging from ½” Diameter to 14″ Diameter Each λ/20 Flat 76.2mm and Larger Includes a Certificate of Calibration Available with Standard Metallic Mirror Coatings: λ/10 and λ/20 Mirrors TECHSPEC Single Surface Optical Flats are used as a reference (test plate) against which the flatness of an unknown surface may be compared. Each piece is precision polished by our master opticians and tested on a Zygo interferometer to insure the surface flatness. The secondary surfaces of our single surface flats are pitch polished to window quality for viewing the interference pattern. TECHSPEC Single Surface Optical Flats ship in a durable storage case for permanent protection. λ/20 flats that are 76.2mm or larger also include a certificate of calibration. Specifications General Type: Interferometry Window Note: Includes a certificate of calibration. Physical & Mechanical Properties Clear Aperture CA (mm): 228.60 Diameter (inches): 10.00 +0.00/-0.04 Diameter (mm): 254.00 +0.00/-1.00 Thickness (inches): 1.50 ±0.10 Thickness (mm): 38.10 ±2.5 Parallelism (arcmin): ≤3 Bevel: Protective as needed Construction: Single Surface Edges: Fine Ground Poisson’s Ratio: 0.16 Young’s Modulus (GPa): 73 Knoop Hardness (kg/mm 2 ): 522.00 Knoop Hardness (GPa): 522 Optical Properties Coating: Uncoated Color: Clear Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More Fused Silica Index of Refraction (n d ): 1.458 Surface Quality: 60-40 Abbe Number (v d ): 67.8 Wavelength Range (nm): 200 – 2200 Surface Flatness (P-V): λ/20 Material Properties Density (g/cm 3 ): 2.20 Coefficient of Thermal Expansion CTE (10 -6 /°C): 0.52 (+5 to +35°C) 0.57 (0 to +200°C) 0.48 (-100 to +200°C) Regulatory Compliance Reach 191: Compliant × RoHS 2015: Compliant × Certificate of Conformance: View ×