3″ Dia. λ/20 Fused Silica Dual Surface Flat

Product Details λ/10 and λ/20 Surface Flatness Options Each λ/20 Flat 76.2mm and Larger Includes a Certificate of Calibration Extended Lifetime in Contact Measurement Applications Single Surface Optical Flats Also Available TECHSPEC Precision Dual Surface Optical Flats are precision ground and polished to the stated accuracies on both surfaces so that either face may be used for test applications. Both surfaces are tested and certified by our Zygo Interferometer. Each flat ships in a durable storage case for permanent protection. TECHSPEC Precision Dual Surface Optical Flats specified for λ/20 flatness that are 76.2mm or larger also include a certificate of calibration. These dual surface flats are uncoated and offered in diameters ranging from 25.40 to 304.80mm. Specifications General Type: Interferometry Window Type of Window: Glass Note: Includes a certificate of calibration. Physical & Mechanical Properties Clear Aperture CA (mm): 68.60 Diameter (inches): 3.00 ±0.04 Diameter (mm): 76.20 ±1.0 Thickness (inches): 0.75 ±0.06 Thickness (mm): 19.05 ±1.5 Parallelism (arcmin): ≤1 Bevel: Protective as needed Construction: Dual 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 Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More Fused Silica (Corning 7980) 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 RoHS 2015: Compliant × Reach 211: Compliant × Certificate of Conformance: View ×