Ray-tracing method optimizes design of nonimaging systems

摘要

Computer-based design programs are now the standard design tool for optimization of imaging systems such as camera lenses and telescopes. Depending on the program, the typical procedure begins with the design of a basic optical system and its approximate operation. The user then defines a "merit function" to constrain the desired performance of the system, and designates which parameters of the initial design are variable. The program then varies these parameters so as to drive the merit function to its optimal value. Because of their much greater generality, nonimaging systems (or non-sequential systems, as they are known in the jargon of ray-tracing) can be much harder to optimize. There are many reasons: generally, nonsequential systems must be traced with many more rays than sequential imaging systems require, and the ray-tracing results are captured on pixelated detectors. Because ray-tracing results are "binned" into pixels, the construction of a merit function that is easily optimizable can be very difficult.