AL5040M-B 50 mm Dia. S-LAH64 High-Precision; CNC Polished Aspheric Lenses; EFL=40 mm; NA=0.55 AR 650-1050nm

The AL5040M-B is a high-precision aspheric lens, designed and manufactured by Thorlabs. This lens is characterized by its 50 mm diameter and a focal length of 40 mm, making it suitable for a wide range of optical applications. The lens is made from S-LAH64, a high-quality optical glass from Ohara, which offers excellent transmission properties in the visible and near-infrared spectrum.

The aspheric design of the lens provides superior optical performance over traditional spherical lenses. It effectively corrects spherical aberration, a common issue in optical systems, which leads to improved image quality and resolution. The lens is CNC polished, ensuring high surface accuracy and excellent optical quality.

The lens features an anti-reflection coating on both the front and back surfaces. This coating, designed for the 650-1050 nm wavelength range, reduces surface reflections, thereby increasing the amount of light transmitted through the lens. The coating also helps to minimize ghosting and flare, further enhancing the optical performance of the lens.

The lens has a numerical aperture (NA) of 0.55, which is a measure of the lens' light-gathering ability. A higher NA allows for a wider angle of acceptance, making the lens more versatile in various optical setups. The lens is 5 mm thick at the edge and 15.5 mm thick at the center, providing structural rigidity and stability.