The LD1357-C is a high-quality bi-concave lens offered by Thorlabs, a leading vendor in the optical industry. This lens, designed with a spherical shape, is ideal for applications that require a negative focal length. The lens is fabricated from N-BK7, a popular glass type known for its excellent optical properties, making it suitable for a wide range of wavelengths.
The LD1357-C has a diameter of 12.7 mm and a thickness of 4.3 mm at the edge, tapering down to 3.5 mm at the center. The bi-concave design features radii of curvature of -52.1 mm for the first surface and 52.1 mm for the second surface, resulting in an effective focal length of -50 mm. The back focal length is -51 mm.
This lens is equipped with anti-reflection coatings on both the front and back surfaces, specifically designed for the ARC 1050-1700nm range. These coatings significantly reduce surface reflections, thereby enhancing the overall transmission of the lens.