Spectrally resolved polarizing interferometer for single-shot line profiling

In this investigation, we describe a spectrally resolved polarizing interferometer to modify the typical spectrally resolved interferometer based on the Fourier method, which has a dead zone caused by the minimum measurable range. By use of a polarization pixelated CMOS camera, which enables us to obtain spatially phase-shifted spectral interferograms, the spectral phase can be extracted with a single image, and the proposed interferometer can obtain a line profile of a specimen at once. By the nature of phase-shifting technique, moreover, the directions of the measured distances can be identified, and the measuring range is extended to twice that of the typical spectrally resolved interferometer. In the experimental results, the measuring range was 104 µm, and the capability to obtain a line profile of a specimen with a single image was confirmed. For 3D surface profiling, lateral scanning was adopted, and the measurement results were compared with the result of the Fourier method.