Automatic initial configuration in off-axis reflective optical system design using combined nodal and Seidel aberration

Currently, an off-axis reflective optical system is designed always from a coaxial initial system, and good imaging performance depends heavily on the choice of good initial configurations. This paper first establishes an imaging-performance evaluation function of the off-axis initial configuration based on nodal aberration theory and Seidel aberration theory. An automatic optimization method of the off-axis initial configuration using the global simulated annealing algorithm is proposed. Two design examples of off-axis three-mirror reflective optical systems are used to demonstrate the effectiveness and simplicity based on the initial configuration design method. Example 1: a series of optical systems with a large 10∘×3∘ field of view (FOV) is quickly and simply implemented using simple surfaces, and the optical systems exhibit perfect imaging quality. Example 2: starting from the good automatic initial configurations, two larger 20∘×3∘ FOV optical systems with focal lengths of 500 mm and f-numbers of five are designed, resulting in good imaging performance and providing a valuable design reference.