|Type||Biconvex Lenses||Material||BK7, UVFS, CaF2, BaF2, Sapphire, ZnSe, Sapphire etc.|
|Clear Aperture||>90%||Diameter Tolerance||+0.0/-0.1mm|
|Thickness Tolerance||±0.1mm||Surface Irregularity||λ/4 @ 633 nm (λ/8 optional)|
|Concentricity||2 arcmin||Paraxial Focal Length||±2%|
A Biconvex Lens, or a Double Convex Lens, is an optical lens having two spherical sides with identical radii of curvature. Biconvex Lenses have positive focal lengths and tend to converge collimated light to a point, their usages include but are not limited to modulation and focus of laser beams and imaging instruments. Biconvex lenses are recommended for the situation where the absolute finite conjugate ratio is equal to 1:1 or close to 1:1. That is when the absolute value /object distance and image distance are equal, and if no, biconvex lenses are still the optimized option for the conjugate ratio between 1:5 and 5:1 (Otherwise plano-convex lenses are more advantageous), functioning to minimize spherical, coma, and distortion.
Hangzhou Shalom EO offers custom Biconvex Lenses made from various materials, including Fused Silica, BK7/N-BK7, BaF2, CaF2, MgF2, Ge, ZnSe, Sapphire, etc. The working wavelengths span the UV to IR spectrum. Custom coating options include uncoated substrates, Broadband Anti-reflection (BBAR) coatings that encompass a certain wavelength range, V-coating which provides lower reflection at a narrower range, and MgF2 AR coatings. Specifications such as diameters, focal lengths, and the f/ number of the biconvex lenses could be tailored upon your requests, and the surface irregularities could be the conventional λ/4, or λ/8 if higher precision is required.