The ring-focus off-axis parabola is an optic that combines the properties of a 90° parabolic focusing mirror with an axicon focusing optic. Typically, ZnSe lenses with a conical term are used to create a ring focus. The ring-focus off-axis parabola eliminates the transmissive optic by combining the axicon with an off-axis parabolic mirror. The resulting geometry is a free-form surface which II-VI generates using slow tool servo technology.
This approach offers versatile design specifications for working distance, ring diameter, and turning angle. For high-power applications, a direct-cooled copper substrate design can be employed.