Processing materials are available in colorless optical glass, laser crystals, fused silica, radiation-resistant glass, UV and IR materials, and metal materials.

This type of lens is thicker at the edges than at the center, and one side is flat. Flat concave lenses are used in optical systems to diverge the beam and increase the focal length. It is often used for beam divergence in high peak energy pulsed lasers. A beam of light incident on a concave surface will be focused at a point outside the instrument.

Sometimes an unanticipated focus may occur and cause the air to overheat or ionize, even affecting the waveform and damaging the instrument. To prevent this, the lens needs to be flipped so that the concave surface is backed up to the parallel beam.

Plano-concave lenses are used for beam expansion, light projection, or to extend the focal length of an optical system. A plano-concave lens has a concave surface on one side and is a lens with a negative focal length. A plano-concave lens should have the flat side facing the focal plane to be treated. Therefore, plano-concave lenses are suitable for use in a variety of applications or industries.