Abstract: One embodiment of a method of calculating an optical surface comprises calculating a meridional optical line of the surface. A ray is selected that passes a known point defining an end of a part of the optical line already calculated. The optical line is extrapolated from the known point to meet the ray using a polynomial with at least one degree of freedom. The polynomial is adjusted as necessary so that the selected ray is deflected at the extrapolated optical line to a desired target point. The polynomial is added to the optical line up to the point where the selected ray is deflected. The point where the selected ray is deflected is used as the known point in a repetition of those steps.

Abstract: One embodiment of a method of calculating an optical surface comprises calculating a meridional optical line of the surface. A ray is selected that passes a known point defining an end of a part of the optical line already calculated. The optical line is extrapolated from the known point to meet the ray using a polynomial with at least one degree of freedom. The polynomial is adjusted as necessary so that the selected ray is deflected at the extrapolated optical line to a desired target point. The polynomial is added to the optical line up to the point where the selected ray is deflected. The point where the selected ray is deflected is used as the known point in a repetition of those steps.