This is a Plano-Concave Spherical Lens, type HO-PVL12.5-02B, manufactured by Holmarc Opto-Mechatronics. The lens has a diameter of 12.5mm and a center thickness of 2.5mm. The effective focal length (EFL) of this lens is -25mm, making it a negative or diverging lens.
The lens is made of N-BK7 Schott glass, a popular choice for its high homogeneity and excellent optical transmission properties in the visible spectrum. The lens's inner and outer radii are both zero, indicating a plano-concave shape.
This lens features broadband anti-reflection (BBAR) coating, designed for the wavelength range of 400-700nm. The BBAR coating reduces reflection and increases transmission, enhancing the lens's performance in the specified wavelength range.
The coating on both the front and back surfaces of the lens is "hol bbbar 0 aoi," indicating a broadband anti-reflection coating with a 0-degree angle of incidence. This coating is designed to minimize reflection and maximize transmission, ensuring optimal performance in most optical systems.