Mathematical Modeling for Losses in Optical Waveguides With Porous Silica Cladding

This paper presents a model to calculate the combined surface and volume scattering losses for optical waveguides containing porous silica materials. The simulation results agree with the published experimental loss data. The model for volume scattering loss considers the primary factors that affect the volume scattering including porosity, volume of pores and scattering cross section. The criteria of Rayleigh scattering was applied to either cylindrical or spherical pores to find the scattering cross section. Surface scattering loss was calculated using Tien's model and the scattering models were applied to optical waveguides reported in previous publications. A good agreement between the experimental results and the models has been demonstrated. The ratio between calculated and experimental results were in the range of (0.9-1). Therefore, these models can be used to calculate scattering losses in optical waveguides including ones with porous silica claddings. Moreover, the scattering models in conjunction with ModeSolver MATLAB simulations have been applied to optical waveguide sensors with porous silica claddings for the first time to validate the possibility of designing LEAC sensors with porous silica claddings.