CaF₂ negative meniscus lens

CaF₂ negative meniscus lens, uncoated（0.18-8µm）

概述

Material: CaF₂ (Calcium Fluoride)
Machinable diameter: Ø1-Ø500mm
Focal length range: 4.5-1000mm
Wavelength range: 0.18-8μm (uncoated), 2-5μm (IR1 broadband anti-reflection film)

The outer convex curvature of CaF₂ negative meniscus lenses (Calcium Fluoride Negative Meniscus Lenses) is greater than the concave curvature, and the focal length is negative, which can reduce the three-order spherical aberration. When combined with another lens, a negative meniscus lens can increase the focal length and thus reduce the numerical aperture (NA). When used to diverge light, to minimize spherical aberration, light should enter from the convex surface of the lens.

The CaF₂ negative meniscus lens is based on calcium fluoride, which has a wide transmission spectral range (180nm-8.0μm), high damage threshold, low fluorescence and high homogeneity. Calcium fluoride has a low refractive index (1.35 to 1.51 in the applicable range), good chemical inertness, and has high hardness characteristics compared with similar materials such as barium fluoride and magnesium fluoride, and is often used in applications with high transmittance requirements in the infrared and ultraviolet spectral ranges.

Dimension-Labs offers a wide range of sizes of uncoated CaF₂ negative meniscus lenses (specific sizes and parameters can be filtered from the details below) and a type of anti-reflection film (IR1 wideband anti-meniscus) to meet the needs of a variety of applications.

General parameters

Material	CaF₂	Effective aperture	>80%
Face	λ/4@632.8nm	Finish	80-50
Design wavelength(nm)	587.6	Focal length tolerance	±1%
Form Tolerance(mm)	+0.0/-0.1	Thickness tolerance(mm)	±0.1
Eccentricity	＜3ˊ	Inverted side	＜0.2×45°