ABSTRACT
This chapter explores some of the applications that are based on passage of a beam through the image-forming optical systems, assuming that there is vacuum or a linear deterministic medium between the system elements. It also explores the evolution of random beams in the human eye, negative phase materials, telescopic systems and laser resonators. Human visual recognition of a distant object is made by perceiving and analyzing light scattered from it. The intensity and the spectral signature of the object play the crucial part in its recognition out of the rest of the environment. Polarization might also play a part but this issue is little studied. The interaction of monochromatic beams with laser cavities was formulated a long time ago. The transverse modes of the resonator, known as the Fox-Li modes, were found to be related to the geometry of the resonator and the characteristics of the light source.
