This is a Plano-Concave Spherical Lens, sourced from CeNing Optics, with a diameter of 12.7 mm and a center thickness of 2 mm. The lens is made of N-BK7 Schott, a popular optical glass due to its excellent optical properties and wide transparency range. The effective focal length (EFL) of this lens is -20 mm, indicating that it is a diverging lens, causing incoming light rays to spread out.
The lens's geometry includes an inner radius of 0 mm and an outer radius of 0 mm, which is typical for a Plano-Concave lens. The concave surface of the lens has a radius of curvature of -10.37 mm. The lens is uncoated, which means it does not have any anti-reflective coating. This may result in higher reflective losses, but it also means that the lens can be used in a wider range of wavelengths.
The lens is designed to be used at a wavelength of 546.1 nm, which is in the middle of the visible light spectrum. It is suitable for use in various applications, including imaging systems, beam shaping, and laser applications. The lens is currently in stock and can be purchased directly from the vendor through the provided web link.