For many years the behavior of collections of optical elements which have the ability to transform the polarization state of light has been studied. These systems not only have been treated as a fundamental problem in optics but have been applied to the development of narrow band filters especially for use in astronomy. Recently it has been shown that collections of such elements can be utilized to transform the temporal shape of short pulses of light. Not only is it possible to transform short pulses into longer distributions but under certain special conditions it is possible to compress pulses temporally. In this paper I will review these achievements beginning with the work of R. Clark Jones and show how an extension of his calculus can be used to formulate optical systems that can be utilized to compress certain optical pulses.