Hangzhou Shalom Electro-optics Technology Co., Ltd. Dia12.7mm EFL-30mm N-BK7 Biconcave Lenses 350-650nm AR Coating 1108-008A

Features: • Double concave structure recommended for absolute conjugate ratio close to 1:1 • Made from N-BK7 (excellent transmission from visible to the NIR region) • Standardized focal lengths and diameters convenient for OEM • Various standard and custom coating options, focal lengths (standard -6 to -100mm) • Applications: Galilean laser beam expander, optical character readers, viewers, and projectors • Custom Biconcave Lenses made from different materials are available Abiconcave lensordouble concave lensis an optical lens with two identical inward-bent spherical surfaces with equal radii of curvature. A double concave lens has a negative focal length and diverges a collimated light beam to the virtual focal point (that is the point at which the extension lines of the diverging light path intersect at the object side of the concave lens). The usages of Biconcave lenses are diverse, encompassing divergence of collimated or focused light beams, beam diameter modulation (e.g., Galilean beam expanders), the correction of spherical aberration of optical assemblies, and increasing the focal lengths of a lens group, etc. Due to its symmetric structure, a double concave lens works best when the conjugate ratio (object distance: image distance) is close or equal to 1:1. In such situations, the distortion, spherical/chromatic aberration, and coma could be offset as a result of the equilibrium of the lenses. Whilst, when the intended magnification ratio is 1/5 or 5/1, a plano concave lens will be a better alternative. This page features Shalom EO’s Off-the-shelfN-BK7 Double Concave Lenses. N-BK7 is a kind of optical glass often used for manufacturing optical components, including lenses. N-BK7 glass is known for its low cost, high optical transmission across the visible spectrum and into the near-infrared region (350-2200nm), low dispersion, high hardness and resistance to scratches and abrasions, and the ability to withstand changes in temperature without significant expansion or contraction. It belongs to the Schott glass catalog, and is one of the most common optical glass materials. Shalom EO’s stockN-BK7 Bi-concave Lenseshave four standard coating options: uncoated, 350-650nm, 650-1100 nm, and 1050-1580nm broadband anti-reflection (BBAR) coatings. Custom V-coatings that exhibit optimized transmission and low-cost MgF2 AR coatings with various transmission wavelengths could be furnished onto the N-BK7 and UVFS biconcave lenses upon request. Besides the stocked N-BK7 and UV Fused Silica Biconcave lenses, Shalom EO also provides off-the-shelf UV Fused Silica biconcave lensesandcustom biconcave lensesmade from BaF2, CaF2, MgF23, Ge, ZnSe, Sapphire, and other optical materials.