Systematic investigation of methods for multiple freeform optimization in multi-lens imaging systems

TL;DR

This paper systematically explores methods for implementing multiple freeform surfaces in multi-lens imaging systems, focusing on optimization strategies, placement, and system performance improvements.

Contribution

It introduces a comprehensive workflow for optimizing and integrating multiple freeform surfaces in optical systems, addressing a gap in current design methodologies.

Findings

Optimal freeform surface placement depends on system eccentricity and freeform parameters.

Different optimization strategies significantly influence system performance.

A practical workflow for multiple freeform surface implementation is proposed.

Abstract

With the development in freeform technology, it has now become more and more feasible to use freeform surfaces in real system designs. While the freeform surfaces helping optical designers achieve more and more challenging system features, the methods for multiple freeform implementations are still underdeveloped. We therefore investigate strategies to use freeform surfaces properly in imaging optical systems with one Scheimpflug system and one lithographic system. Based on the studies of the influences of the freeform normalization radius, freeform order and system eccentricity, the methods of determining the optimal location for implementing one freeform surface are discussed. Different optimization strategies to optimize two freeform surfaces are discussed to compare their resulting influences on the system performance. On top of that, ways to implement more than one freeform surface in the optical system is also investigated. In the end, a workflow is presented as guidance for implementing multiple freeform surfaces with respect to system aberration constitutions.