Flat concave cylindrical lens is an optical product, which forms a divergent linear virtual image, which is used to control the size of only one direction of the beam.
The material of this lens is BK7, so it is not suitable for ultraviolet wavelength. Compared with spherical lens, cylindrical lens is more difficult to manufacture. We reasonably select materials (texture, bubbles, impurities, uniformity), pay attention to the factors affecting the scattering (scratch, dent, gloss), and high-quality grinding.
Lenses can be divided into uncoated and visible band antireflection multilayers.
The design wavelength of the lens is 546.1 nm (E-line of green mercury line). Since the focal length changes with the wavelength, when it is used for other wavelengths, the focal length also changes.