Temperature determination with radial basis functions means of a nonlinear common path interferometer

Interferometers are used to measure physical magnitudes such as gradients of pressure, temperature, refractive index, deformation, etc. The common objective of these techniques is to produce a pattern of fringes modulated in phase by the physical amount to be measured The optical tomography is a nondestructive technique that allows us to obtain information about the distribution of these physical magnitudes on the basis of these interferograms. In this work, a non‐iterative algebraic reconstruction technique is shown to obtain the distribution of temperature gradients of a radial phase object, fitting non‐local radial basis Gaussian functions to the diagram level curves given by the interferogram orders. This method is numerically accurate and fast in any computational platform; in addition, it is easy to program. An example is shown: the temperature gradients of a lighter flame. This interferogram was obtained with a common path interferometer that uses a nonlinear material to photoinduce the required filter.