Calculation of Refractive Index Changes from Thermal Lens Fringes using Continuous Wavelet Algorithm

Thermal lens fringes are obtained on the nile-blue/ethanol solution by illuminating it with a He–Ne laser in a Mach–Zehnder interferometer. The refractive index change distribution of these fringes is calculated by using two different continuous wavelet transform (CWT) algorithms. It is concluded that the CWT-phase method works better than the CWT-gradient algorithm for the analysis of thermal lens fringes according to theoretical results.