This is a Plano-Concave Lens, type SLB-15-70NM, offered by OptoSigma. The lens has a diameter of 15.0 mm and a focal length of -70.0 mm, making it suitable for a variety of optical applications. The lens is made of n-bk7 schott material, a popular choice for its high refractive index and low dispersion.
The lens features a spherical shape, with a front surface radius of -36.33 mm and a back focal length of -71.3 mm. The edge thickness of the lens is 2.8 mm, while the center thickness is 2 mm. The lens is coated with opt m on both the front and back surfaces, enhancing its transmission capabilities within the 400-700nm wavelength range.
The lens is currently in stock and available for immediate purchase. For more information, please refer to the vendor's website using the provided weblink.