GENERALIZED RAY TRACING, CAUSTIC SURFACES, GENERALIZED BENDING, AND THE CONSTRUCTION OF A NOVEL MERIT FUNCTION FOR OPTICAL DESIGN.

It is shown that the displacement of a caustic point caused by a generalized bending is in essentially a straight line, that the direction of the displacement is determined by which refracting surfaces are selected, and that the magnitude of the displacement is proportional to the logarithm of the bending parameter. This indicates that caustic surfaces can be used as a merit function in the optical design process, that the merit functions can be calculated by means of generalized ray tracing, and that generalized bending provides an effective means of optimizing the design when included in a feedback loop.