Biography
Biography: Sunggoo Cho
Abstract
Parabasal theory is a technique in geometrical optics that describes the behavior of light rays located near some defined base ray rather than the optical axis. In this work, we are concerned with parabasal rays which lie in a sufficiently small neighborhood of a chief ray and develop some formulas for parabasal quantities of the chief ray. Parabasal quantities of a chief ray are shown to be intimately related to the coeffi cients of fi rst order differential equations of the chief ray. Using the relations, we derive parabasal formulas containing parabasal refractive indices and parabasal powers from the first order differential equations. Th ese parabasal formulas turn out to be decoupled diff erential equations of the fi rst order diff erential equations so that highly coupled diff erential equations for a chief ray can be solved systematically. In addition, we apply parabasal formulas to the paraxial region by taking the limits of the formulas. Th ese limits give necessary conditions expressed in terms of Gaussian brackets for various initial design requirements of optical lens systems. Th ose necessary conditions do not seem to be derivable by using only paraxial theory without parabasal approaches developed in this work.