This is a HO-BVL25-1.6B 25mm diameter N-BK7 double-concave lens, featuring an effective focal length (EFL) of -40mm and broadband anti-reflection (BBAR) coating for the wavelength range of 400-700nm. The lens is sourced from Holmarc Opto-Mechatronics, a reputable vendor in the optical industry.
The lens is a spherical design, having a base shape of a circle. It has a diameter of 25mm and a center thickness of 2.5mm. The lens's front and back surfaces have radii of curvature (R1 and R2) of -42.771859mm and 42.771859mm, respectively. The lens's inner and outer radii are both 0mm, indicating a symmetrical double-concave shape.
The lens is made of N-BK7 glass, a popular material for optical elements due to its excellent optical properties. The lens features BBAR coating on both the front and back surfaces, which significantly reduces reflection losses and improves transmission in the specified wavelength range.
The item data indicates that the lens is in stock and available for immediate purchase. For more information, consult the vendor's website at https://www.holmarc.com/bi_concave_lenses.php.