Find preliminary solution of zoom objective lens using gaussian optics and third-order aberration theory

Despite the optical design softwares like ZEMAX and CODE V own the strong optimization features, the selection of preliminary solution is still critical if a good design result is expected. A common practice for finding a preliminary solution is to scale an existing optical system or one of its components. However, this approach has a certain blindness. Another method is using the Gaussian optics and the third-order aberration theory to find the initial solution of the zoom objective lens. This approach is helpful to produce innovative ideas in design but is rarely used. The ideas, concept, experiences, and results generated by this approach are introduced in this paper. Through the design example of a ten-fold zoom objective lens, the process of finding the preliminary solution is introduced in detail. In order to verify the initial solution obtained, the aberration optimization is also performed using ZEMAX. For the sake of increasing power of conviction, specific data is given at each step of the design process, including the final results obtained by ZEMAX optimization.