This is a Plano-Concave Lens from Laser Components, a renowned vendor in the optical industry. The lens, with a diameter of 25.4 mm, is made of N-BK7 Schott, a popular material for its excellent optical properties. The lens's base shape is circular, and it features a concave shape with an inner radius of 0 and an outer radius of 0.
The lens's geometry includes a center thickness of 2 mm and an effective focal length (EFL) of -600 mm, making it suitable for applications requiring negative focal lengths. The lens is uncoated, which means it does not have any additional layers to enhance its optical properties. However, this also means that it can be easily customized with a coating of your choice.
The lens is designed to work with a wavelength of 633 nm, making it suitable for a wide range of applications in the visible light spectrum. It is currently in stock and available for immediate use. For more detailed information, you can refer to the datasheet provided by the vendor.