355230-C 6.325 mm Dia. D-ZLAF52LA Molded Glass Aspheric Lenses; EFL=4.5 mm; NA=0.55 AR 1050-1700nm

The 355230-C is a high-quality aspheric lens, manufactured by Thorlabs, designed for use in a wide range of optical applications. This lens is molded from D-ZLAF52LA glass, a material known for its excellent optical properties and durability. The lens has a diameter of 6.325 mm and a thickness of 1.688 mm at the edge, making it suitable for use in compact optical systems.

The lens features an effective focal length (EFL) of 4.5 mm, which is a crucial parameter in determining the lens's magnification power. The EFL, combined with the lens's high numerical aperture (NA) of 0.55, allows for a wide field of view and high light-gathering capability, making this lens ideal for use in imaging systems and other applications where high light-gathering efficiency is required.

The lens's aspheric design helps to correct spherical aberration, a common optical problem that can degrade image quality. This is achieved through the precise shaping of the lens's front and back surfaces, which are defined by high-order polynomial equations. The front surface of the lens has a radius of curvature (R1) of 0 mm, while the back surface (R2) has a radius of -3.576018 mm.

The lens is coated with a broadband anti-reflection (AR) coating, designed to reduce surface reflections and increase transmission in the 1050-1700 nm wavelength range. This coating helps to improve the overall efficiency of the optical system and reduces the risk of unwanted reflections and ghost images.