This is a Plano-Concave lens, a type of spherical lens, sourced from Qioptiq Photonics. The lens has a base shape of a circle and a diameter of 22.4 mm. The center thickness of the lens is 1.5 mm. The effective focal length (EFL) of this lens is -50 mm, making it a negative or diverging lens. This lens is designed to operate within the wavelength range of 725-1050 nm, with a central wavelength of 588 nm.
The lens is made of N-BK7, a type of glass commonly used in optical applications due to its excellent optical properties. The lens is unmounted, providing flexibility for users to mount it according to their specific requirements.
The lens features a broadband anti-reflection coating on both the front and back surfaces. The coating, identified as 'qio bbar arb2nirnbk7', is designed to reduce reflection and increase transmission across the specified wavelength range.