Effective Optical System Assembly Using Ultra-Precise Manufactured References

Abstract

The present work demonstrates that exactly manufactured references for joining, mounting, and metrology purposes are crucial in the effective assembly of high-quality optical systems. Based on the alignment turning of spherical and aspherical lenses, the proposed approach can be transferred to non-rotational symmetric elements such as prisms, active components (e.g., laser diodes), and freeform mirrors. The complexity of the optical component decides whether on-machine metrology or specific measurement setups need to be used to determine the position and orientation of the references with respect to the optical function. The resulting correction data are considered during the machining process. The subsequent correction cycle realizes mounting and metrology references down to sub-micron precision using diamond-machining techniques. This approach facilitates the assembly of demanding optical systems and even freeform arrangements in a predictable and passive manner. Different machining setups as well as the corresponding metrology approaches are demonstrated, and results are presented for representative components. The effectiveness of the approach is discussed using rotationally symmetrical lens systems and a snap-together freeform mirror system.