Describes a lens with one flat (planar) face and one concave face, giving it a negative focal length. These lenses diverge collimated beams and are commonly used to expand laser beams or increase focal lengths in existing optical systems.
Heard on the job
Put a planoconcave lens in front of the objective to spread the beam out before it hits the target.
Also heard as
- plano-concave
- PCV
Related terms
Planoconvex
A lens shape featuring one flat surface and one outwardly curved surface.
Beam expander
A pair of lenses arranged as a telescope that enlarges a collimated beam's diameter and cuts its divergence.
Divergence
How fast a laser beam spreads with distance far from its waist, given as an angle in milliradians.