A single analytical formulation for evaluating the focal shift in any apodized nontelecentric focusing setup is reported. The formulation is also useful in the case of imaged paraxial beams. We show explicitly that the magnitude of the focal shift is determined by only one parameter that depends on the effective width of the pupil filter and its axial position. To illustrate our approach we examine different focusing setups.
© 2001 Optical Society of America
M. Martínez-Corral, M. T. Caballero, L. Muñoz-Escrivá, and P. Andrés, "Focal-shift formula in apodized nontelecentric focusing systems," Opt. Lett. 26, 1501-1503 (2001)