Measuring device and recording medium utilizing a polarized light phase difference to obtain a stress distribution

Abstract

Included are: an interference unit that combines reference light with reflected light from a measurement object, separates the combined light into two orthogonal beams of polarized light, converts the two beams of polarized light into two analog electrical signals, and outputs the two analog electrical signals; an analog-to-digital converting unit that converts the two analog signals into digital electrical signals and outputs the digital electrical signals as two digital signals; and a calculation processing unit that converts the digital electrical signals corresponding to the two beams of polarized light into frequency spectra for each of beams of light emitted from an light emitting unit, calculates an optical path length difference between the reference light and the measurement light, obtains a polarized light phase difference between the two beams of polarized light for each of the beams of light, and obtains wavelength dependency of the polarized light phase difference.