Freeform off-axis optical system with multiple sets of performance integrations.

Freeform optical surfaces make it possible and feasible to design systems with novel functions. In this Letter, a new type of freeform system with multiple sets of performance integrations is proposed, for the first time to the best of our knowledge. The system can operate at different optical parameters for different imaging demands. A movable aperture stop is used in the system for switching between the working areas suited for different sets of optical parameters. A construction method for integrated freeform surfaces is proposed herein, which considers multiple object-image relationships simultaneously. By this method, three integrated freeform systems were designed with different novel functions. This Letter adds more variety to the design of freeform off-axis systems.