In this course, propagation through miniaturized or micro-structured optical systems and components, optical systems for novel applications and relying on merit functions defined by the field representation of light are demonstrated. The light coupling efficiency into a fiber is an example of such a merit function. modern optical design concepts like amplitude matching require a field representation of light. Optical systems design that take the light and its waves into consideration is appropriately called wave-optical engineering or physical-optical system design. This course shows why this field is becoming a widely used way of obtaining innovative solutions to optical design problems.