Design and development of optimized scattering structures and fabrication using stereolithography apparatus

Abstract

A disordered structure is the one which causes multiple scattering events to the light entering the medium and as a result of which it undergoes a random path of propagation. There has been a growing interest around random scattering structures due to their increased effectiveness in light localisation. In this project, the design of random scattering substrates is done using Computer Aided Design (CAD) software and are fabricated using Stereolithography 3D printing technique. The optimisation of random substrates is carried out by varying the dimensions, orientations and density of the shapes with a specific grid pattern. 3D printed substrates are characterised using confocal microscopy and the effectiveness of the light localisation is quantified using Coherent Backscattering (CBS) measurements. The concept of using randomness for effective light localisation can be incorporated to sensing applications including microfluidics. Here, we use the substrates with random microfluidic channels for photoluminescence spectroscopy based chemical sensing of Rhodamine 6G. In short, this research is focused on investigating the fundamental performance of light localisation in 3D printed micro-scale random scattering structures and their application in microfluidic sensing.