Thermodynamic theory of nonlinear multimoded photonic systems

Author: Alexander Shukakidze
Keywords: Photonics, Optics, Thermodynamics, Statistical Physics
Annotation:

Lately there has been a renewed interest in studying nonlinear multimoded optical systems, namely optical systems consisting of thousands of optical fibers such as high-speed communication structures. The complexity of interactions in these systems is the reason to numerous exceptional optical effects. The somewhat chaotic processes that take place in these systems had led to several theoretical challenges which we aren't capable of overcoming by using classical approaches. This work starts by deriving and solving the discrete Schrödinger equation for such systems. Analogies with Quantum and Classical Mechanics are shown. In the following part a thermodynamic framework capable of describing the intricate behavior of such photonic configurations is built. New physical observables like the "Internal Energy" (the mean value of the propagation constant) and the "Optical Entropy" are defined. A new equation of state analogous to that of the conventional thermodynamics is obtained. It is also shown that the optical power together with the "Internal Energy" always flow with respect to the second law of thermodynamics. Lastly, laws of isentropic processes are obtained and the possibility of realizing processes similar to the Carnot Cycle in such photonic systems is presented.