25mm Dia. x -50mm FL, VIS-NIR Coated, Double-Concave Lens

Product Details AR Coated to Provide <1.25% Reflectance per Surface for 400 - 1000nm <0.25% Reflectance @ 880nm Designed for 0° Angle of Incidence Various Coating Options: Uncoated , VIS-EXT , MgF 2 , VIS 0° , NIR I , and NIR II TECHSPEC VIS-NIR Coated Double-Concave (DCV) Lenses are designed to have two inward curved surfaces and a negative focal length similar to Plano-Concave (PCV) lenses. These lenses can be used for balancing aberrations created by other lenses within a system due to their negative spherical aberration. Double-Concave (DCV) lenses are commonly used in a variety of applications including image reduction, beam expansion and telescopes. TECHSPEC VIS-NIR Coated Double-Concave (DCV) Lenses are optimized for transmission (>99%) in the near-infrared. These lenses are also available Uncoated , VIS-EXT , MgF 2 , VIS 0° , NIR I , or with NIR II AR coating options. Specifications General Type: Double-Concave Lens Physical & Mechanical Properties Diameter (mm): 25.00 +0.0/-0.025 Center Thickness CT (mm): 2.50 ±0.10 Edge Thickness ET (mm): 5.40 Centering (arcmin): <1 Clear Aperture CA (mm): 24.00 Bevel: Protective as needed Optical Properties Effective Focal Length EFL (mm): -50.00 Focal Length Specification Wavelength (nm): 587.6 Back Focal Length BFL (mm): -50.82 Substrate: Many glass manufacturers offer the same material characteristics under different trade names. Learn More N-BK7 f/#: 2.00 Coating: VIS-NIR (400-1000nm) Coating Specification: R abs ≤0.25% @ 880nm R avg ≤1.25% @ 400 - 870nm R avg ≤1.25% @ 890 - 1000nm Wavelength Range (nm): 400 - 1000 Surface Quality: 40-20 Power (P-V) @ 632.8nm: 1.5λ Irregularity (P-V) @ 632.8nm: λ/4 Focal Length Tolerance (%): ±1 Radius R 1 =-R 2 (mm): -52.10 Numerical Aperture NA: 0.25 Damage Threshold, By Design: Damage threshold for optical components varies by substrate material and coating. Click here to learn more about this specification. 5 J/cm 2 @ 532nm, 10ns Regulatory Compliance RoHS 2015: Compliant × Certificate of Conformance: View × Reach 235: Compliant ×