• Diameter: Ø25.4 mm
• UV AR Coating for the 290 - 370 nm Range
• Focal Length: 150 mm
• Fabricated from UV Grade Fused Silica
• Spherical Surface Power: 3 Fringes
• Spherical Surface Irregularity: λ/4

Thorlabs' UV Grade Fused Silica Positive Meniscus Lens has a UV antireflection coating for the 290 - 370 nm range deposited on both surfaces. Compared to N-BK7, UV-grade fused silica offers high transmission deeper into the UV (down to 185 nm), better homogeneity, and a lower coefficient of thermal expansion. In addition, UV-grade fused silica exhibits virtually no laser-induced fluorescence (as measured at 193 nm), making it an ideal choice for applications from the UV to the near IR.

The additional UV antireflection coating on these positive meniscus lenses is particularly desirable for applications with multiple optical elements. Since approximately 4% of the incident light is reflected at each surface of an uncoated substrate, the application of a UV AR coating improves transmission, which is particularly important in low-light applications, and prevents the undesirable effects (e.g., ghost images) associated with multiple reflections.

Positive meniscus (convex-concave) lens, which is thicker in the middle than at the edges and cause light rays to converge, is designed to minimize third-order spherical aberration. When used to focus a collimated beam, as shown in the diagram above, the convex side of the lens should face the source to minimize spherical aberration. It is often used in conjunction with other lenses to decrease the focal length, and therefore increase the numerical aperture (NA), of an optical assembly. Since a positive meniscus lens has a greater radius of curvature on the concave side of the lens than on the convex side, real images can be formed.

• Lens Shape: Positive Meniscus
• Diameter: Ø25.4 mm
• Diameter Tolerance: +0.00 mm / -0.10 mm
• Substrate Material: UV Grade Fused Silica
• AR Coating Range: 290-370 nm
• Reflectivity Over Coating Range(AOI = 0°): R_avg <0.5%
• Transmission Internal: ≥ 88%/cm @ 185 nm
• Focal Length Tolerance: ±1%
• Surface Quality: 40-20 Scratch-Dig
• Clear Aperture: >90% of Diameter
• Design Wavelength: 588 nm (n=1.460)
• Index of Refraction: (@ Design λ) 1.460
• Centration: ≤3 arcmin
• Diameter: 25.4 mm
• f: 150 mm
• R₁: 47.6 mm
• R₂: 149.8 mm
• t_c: 3.2 mm
• t_e: 2 mm
• f_b: 146.8 mm
• Suggested Mount: LMR1