Numerical study of radiative transport, hydrodynamics, and chemical kinetics in a photodissociation atomic iodine amplifier

Index-of-refraction changes induced by hydrodynamic activity have been blamed for poor beam quality in photodissociation lasers. Until recently, the pump field, hydrodynamics, chemical kinetics, and the lasing field have been decoupled in theoretical models because of the wide range of time scales on which they act. Although these mechanisms occur at varying time scales ranging over seven orders of magnitude (subnanosecond to milliseconds), each mechanism strongly affects the others. In this paper the authors present a model that first coupled the pump field, chemical kinetics, and hydrodynamics in the form of implicit and explicit finite-difference equations. The authors then couple in the laser field to show that index-of-refraction changes induced by radiative transfer degrade peak beam intensity