A Unified Materials Approach To Mitigating Optical Nonlinearities In Optical Fibre. Iia - Material Additivity Models And Basic Glass Properties

In part IIa of this paper describes the continuum models employed to deduce the physical, acoustic and optical properties of optical fibres that exhibit intrinsically low optical nonlinearities. The continuum models described are based on the additively approaches of Winklemann and Schott (WS). Initially developed over 120 years ago, WS additively works well for predicting the basic properties of bulk silicate glasses. While high-silica-content glasses are still the gold-standard for telecommunication and high energy laser fibres, the models have been systematically expanded to include deduction of the physical, thermophysical and acoustic constants and coefficients that bear on parasitic nonlinearities. The state-of-the-art in WS-based continuum materials models is reviewed with specific examples provided based on canonical material systems suggested from the findings of Part I of this paper, and treated in detail in Part III.