New Principles of Synthesis and Optimization of Optical Systems Using a Computer

Abstract

The progress of optical system design using a computer has been developed basically in the direction of increasing the possibilities of the software for ray tracing through various types of optical surfaces and elements which form multi-configuration optical systems. Such software helped to fulfil calculation of geometric and diffraction characteristics of the image quality, to develop optimization methods used for reducing aberrations of separate rays and different characteristics of optical systems to the desired values. They permitted to expand service functions for graphic representation of the results of calculation and for interaction of a designer with a computer. No doubt the available software for optical system design is a great achievement of applied optics. The software gives a designer an instrument of the highest capacity for designing complex optical systems. This notwithstanding a subjective role of a designer shouldn't be eliminated by any means. The design of optical systems still remains in many respects a kind of “an art” depending on a designer, and it isn't “an applied science” which strictly and unambiguously algorythmizes the process of designing. As we know from the original sources there's no formalized approach to the synthesis of an initial optical system in the majority of software. On the base of specification requirements such synthesis makes possible to found the constructive parameters of the initial optical system suitable for further optimization and analysis. It's assumed that the said initial optical system is already existing or a designer is somehow creating it independently. On the other hand the optimization programs possess the substantial local limitedness caused by multi-extremeness of the minimized merit function, and in the majority of cases optimization doesn't bring to the acceptable solution. This fact substantially reduces efficiency of using such programs. In accordance with the foregoing the author’s researches were directed to the more complete formalization of the process of optical system design, to the decrease of subjective, heuristic stages and to transformation of “the art” of design into “the science” of design. In the present paper I'll briefly expound theoretical approaches of an initial optical system synthesis and pseudo-global optimization. The suggested methods are founded on the base of development of analytical theory of aberrations of the third order, expansion of aberration functions in terms of the orthogonal Zernike's polynomials and on the base of using the specifically determined physical criteria of rationality of optical system construction.