Wide-field parallel mapping of local spectral and topographic information with white light interference microscopy

Abstract

Fourier analysis of interferograms captured in white light interference microscopy is proposed for performing simultaneous local spectral and topographic measurements at high spatial resolution over a large field of view. The technique provides a wealth of key information on local sample properties. We describe the processing and calibration steps involved to produce reflectivity maps of spatially extended samples. This enables precise and fast identification between different materials at a local scale of 1 µm. We also show that the recovered spectral information can be further used for improving topography measurements, particularly in the case of samples combining dielectric and conducting materials in which the complex refractive index can result in nanometric height errors.