69-143 50mm Dia. L-BAL35 Calibration Grade Aspheric Lens; EFL=37.5mm; NA=0.66 Uncoated

The 69-143 is a high-quality Calibration Grade Aspheric Lens, sourced from the renowned optical vendor, Edmund Optics. This lens, with a diameter of 50mm, is designed for use with a numerical aperture (NA) of 0.66, making it a versatile choice for various optical applications.

The lens is made from L-BAL35, a material from Ohara, a leading manufacturer of optical glass. This material is known for its excellent optical properties, making it an ideal choice for high-precision optical systems. The lens is uncoated, which means it does not have any additional layers to enhance its optical properties. However, this does not affect its performance in calibration tasks, where the primary focus is on precision and accuracy.

The lens has an effective focal length (EFL) of 37.5mm, which is the distance from the center of the lens to the point at which it focuses light. This EFL makes the lens suitable for use in moderate-distance optical systems. The lens also has a high refractive power, thanks to its high NA, which allows it to focus light more tightly than lenses with lower NA values.

The geometry of the lens is also noteworthy. It has a center thickness of 19.4mm and an edge thickness of 2.69mm. The front surface of the lens has a radius of curvature of 22.092mm, while the back surface is flat. This asymmetry gives the lens its aspheric shape, which helps to correct spherical aberration and other optical aberrations, leading to sharper, clearer images.