MULTIPHYSICS CO-OPTIMIZATION OF OPTICAL FIBER MATERIALS AND WAVEGUIDE STRUCTURES FOR NONLINEARITY CONTROLLED HIGH SPEED TRANSMISSION

Abstract

High-speed optical communications systems have been developed at an extremely rapid pace, and it is essentially limited by fiber nonlinearities, chromatic dispersion, and material-induced attenuation, which diminish signal integrity at rates of terabits per second. Traditional optimization of optical fiber using single parameter does not deal with the interaction between material composition, geometry of the waveguides, thermal effects, and nonlinear optical effects. The paper suggests a multiphysics co-optimization scheme of optical fiber materials and waveguide design to obtain a controlled nonlinearity of the system and better high-speed transmission performance. The first is to reduce nonlinear coefficient (. gamma ) dispersion (D ) and attenuation (. alpha ) and to maximize effective area (A eff ), bandwidth and signal-to-noise ratio (SNR). The target materials are germanium, fluorine and nanostructured inclusions doped engineered silica based composites to optimize refractive index contrast and nonlinear refractive index (n2). Some properties of importance included are Kerr nonlinearity, group velocity dispersion, thermo-optic coefficient, mechanical stability and optical loss. The suggested procedure combines the approach of the finite element multiphysicsmodeling (optical-thermal-structural coupling) with a hybrid Particle Swarm Optimization-Genetic Algorithm (PSO-GA) algorithm to investigate the global parameters. A physics informed surrogate model has a higher speed in convergence and accuracy. Compared to traditional step-index and dispersion-shifted fibres, it has shown a 22 percent decrease in nonlinear coefficient and 18 percent in dispersion flattening and 15 percent in Q-factor in 400 Gbps transmission. The co-optimized design is also 27% more effective mode area and reduced nonlinear penalties in circumstances of higher launch power. This paper is further generalized to next-generation coherent optical networks, space-division multiplexing systems, and ultra-long-haul communication links, which provide a pathway to nonlinearity-controlled high-capacity fiber transmission, which is scalable and computationally efficient.