Freeform optics alignment strategy and its effect on development of precision freeform optics

Freeform optics is the next generation optics with no rotation symmetry about any axis. The fabrication and metrology of freeform optics are not possible by conventional techniques. Due to non-symmetric nature, it is more critical to align the freeform surface during fabrication and metrology. Fabrication and metrology accuracies of the freeform optics are mainly limited due to alignment errors at all the stages of development process. In this paper, effects of alignment errors on quality of freeform optics during of fabrication and metrology are studied. It is found that alignment errors have significant contribution on quality of freeform optics development. Different types of fiducials and their importance and utilization are discussed. Further, a strategy for effective alignment of freeform optics is proposed.