A spherocylindrical lens has one surface with a spherical curvature and another with a cylindrical curvature. This geometry gives the lens different optical powers in orthogonal axes, allowing it to correct astigmatism or shape a circular laser beam into an ellipse. In optics labs, these are often custom-made or assembled from separate spherical and cylindrical elements to precisely control beam divergence in one specific axis.
Heard on the job
We need a spherocylindrical optic to circularize the highly astigmatic output from this laser diode.