Paraxial optics is sometimes known as the Gaussian optics. It is the simplest framework where optical systems are described. A great variety of textbooks in optics include specific chapters to the paraxial approximation of the geometrical optics. Other textbooks focused in geometrical optics propose that the paraxial treatment should be included as part of the first approach to the subject. The...

As well as the geometrical methods used for solving lens problems, and locating the size and position of images in optical systems, there is an alternate, perhaps more versatile, method involving matrix manipulation. Many of you will be familiar with the use of simple 2x2 matrices. Firstly, however, before I consider the use of matrices in optics, I will review the matrix solution of two simult...