In many applications, spherical mirrors, cylindrical mirrors, and parabolic mirrors help shape the laser beam. Biconic mirrors -- or the more general toroidal mirrors -- can combine two separate optics into one.
Biconic mirrors have two different radii on one surface. It is possible to make a biconic mirror with spherical curves or aspheric curves, depending on the application and need to eliminate aberrations. When appropriately designed, they can replace common 90° bending mirrors to recollimate a laser beam in a long delivery path.