Software package for thoretical simulations of nonlinear light propagation in photochemical systems

点击翻译按钮获取中文摘要

The patterns of clouds in the sky, the wind-sculpted striations in the desert sand, the spots and stripes of animal skin are examples of patterns that emerge spontaneously in nature. The physical laws that govern spontaneous pattern formation in these dissimilar systems are strikingly similar. Any system that is unstable (prone to change) will spontaneously transform in an attempt to reach its most stable state (equilibrium). Patterns emerge if during its evolution towards equilibrium, the system is subjected to two opposing forces. Our research examines such nonlinear phenomena when a system simultaneously undergoes optical and chemical changes. We have discovered a richly diverse suite of nonlinear phenomena including self-trapped beams of light, which travel without broadening over unexpectedly long distances. We have found self-trapped beams of both laser and separately, of white light and learnt that their properties are fundamentally different. Waves composing a laser beam possess the same wavelength and are strongly correlated to each other. Exactly the opposite is the case for white light, which is said to be incoherent because it is composed of an entire spectrum of wavelengths and has extremely poor correlation. Once self-trapped, a laser beam exhibits different and discrete optical modes - like the vibrational modes of a drum skin or the harmonics of a violin string. The optical modes of a self-trapped white light beam however fluctuate so rapidly that only a time-averaged or smoothed profile of the entire beam can be observed. By applying our knowledge of the competition between diffraction and refraction in self-trapping behaviour, we have recently been able to demonstrate the spontaneous formation of patterns in large uniform beams of white light. While all of these studies have been conducted through experiments in the laboratory, they must now be completed with theoretical studies. This application requests funding to purchase software that will enable us to theoretically simulate and model the behavior of these systems and in this way, help in the design of further experiments.