* Diameter (metric): 12,5 - 40,0 mm
* Diameter (imperial): 0.5 - 1.5 inch
* Diameters up to 4 inch available on request
* Focal length from -25 mm to -1000 mm
Plano-Concave (PCV) lenses have negative focal lengths and are used to diverge collimated incident light. They form only virtual images which are seen through the lens and reduce spherical aberration, coma and distortion at negative-infinite or near-infinite conjugate ratios.
These lenses are thicker at the edge than in the centre and flat on one side. The plano-concave lenses are used to expand light beams or to increase focal lengths in optical systems. They are often employed for beam expansion of high peak power pulsed lasers. A beam incident on a concave surface will be focused to a point outside the instrument.