69-144 50mm Dia. L-BAL35 Calibration Grade Aspheric Lens; EFL=50mm; NA=0.5 Uncoated

The 69-144 is a high-quality Calibration Grade Aspheric Lens, boasting a diameter of 50mm and a numerical aperture (NA) of 0.5. This lens is sourced from the reputable vendor, Edmund Optics, and is available for purchase through their website.

This lens is crafted from L-BAL35, a material identified by the catalog number "69-144". The lens is uncoated, which can be advantageous in certain applications where coating might introduce unwanted artifacts or alter the optical properties.

The lens geometry is intricately designed, with an inner radius of 0mm and an outer radius of 0mm. The diameter of the lens is 50mm, and it has a thickness of 7.85mm at the edge and 19.4mm at the center. The effective focal length (EFL) is 50mm, and the back focal length (BFL) is 37.79mm.

The aspheric shape of the lens is defined by its radii (r1 and r2), which are 29.456mm and 0mm respectively. The lens's conic constant (k1) is -1.431442, and higher-order aspheric terms (k2, k3, etc.) are not specified, indicating that this is a second-order aspheric lens.

The lens's NA is 0.5, which is a measure of its light-gathering ability and the convergence angle of the light it focuses. The refractive index of the lens material is not specified, but it can be calculated using the formula NA = n*sin(α), where n is the refractive index and α is the half-angle of the maximum cone of light that can enter or exit the lens.

This lens is suitable for use in a wide range of applications, particularly where high precision and quality are required. Its calibration grade ensures it meets stringent quality standards, making it an excellent choice for metrology, interferometry, and other precision optical applications.