49-101 25 mm Dia. L-BAL35 Precision Aspheric Lens; EFL=18.75mm; NA=0.66 BBAR 425-675nm

The 49-101 is a high-precision aspheric lens, boasting a 25 mm diameter and a numerical aperture (NA) of 0.66. This lens is designed for use in the visible spectrum, specifically at a wavelength of 587.6 nm.

The lens is crafted from L-BAL35, a material sourced from Ohara, a renowned manufacturer of optical glass. This material is known for its excellent optical properties, making it an ideal choice for high-performance optical systems.

The lens features an effective focal length (EFL) of 18.75mm, which is the distance from the lens's principal point to its focal point. This EFL, combined with the lens's high NA, allows for a wide field of view and high light-gathering capability.

The lens's geometry is carefully designed to optimize its performance. It has an inner radius of 0 mm and an outer radius of 0 mm, which contributes to its high NA. The lens's thickness at the edge is 1.63 mm, while its thickness at the center is 10 mm. The front and back surfaces of the lens are coated with BBAR 425-675nm, a broadband anti-reflection coating that reduces surface reflections and improves transmission in the 425-675 nm range.

The lens's shape is aspheric, which means it has a non-spherical surface. This design helps to correct spherical aberration, a common optical issue that can degrade image quality. The lens's asphericity is defined by its conic constant (k1), which is -0.753209.