My background is of undergraduate level electrodynamics, quantum mechanics, statistical mechanics, and so on.
I'm going to assume that you have some experience with information theory as it relates to computation theory. This book:
is a good foundational look at how optical computing works, combining the physical processes with the computational understanding.
This paper will provide a more up-to-date overview of where the state of optical computing is today: http://www.hindawi.com/journals/aot/2010/372652/ and more importantly provide further direction on where to look for more information.