A230-B 6.34 mm Dia. S-NPH1 Molded Glass Aspheric Lenses; EFL=4.51 mm; NA=0.55 AR 650-1050nm

The A230-B is a high-quality aspheric lens from Thorlabs, designed with a 6.34 mm diameter and a molded glass construction using the S-NPH1 material from Ohara. This lens is specifically designed for use with a wavelength of 780 nm, making it suitable for a wide range of applications in the optical field.

The lens features an effective focal length (EFL) of 4.51 mm, which is the distance from the lens's principal point to its focal point. This EFL, combined with the lens's 0.55 numerical aperture (NA), allows for a wide field of view and high light-gathering capability. The NA is a measure of the lens's ability to gather light and focuses it onto a small spot.

The A230-B's geometry includes a center thickness of 2.94 mm and an edge thickness of 1.36 mm, providing excellent structural integrity. The lens's front and back surfaces are coated with a broadband anti-reflection coating, specifically designed for the 650-1050 nm range. This coating reduces surface reflections, increasing the amount of light transmitted through the lens.

The lens's aspheric design corrects spherical aberration, a common issue in traditional lenses where light rays do not converge at a single point, leading to blurry images. The aspheric design ensures that all light rays converge at the same point, resulting in sharper images.