Patent ID: 9080861
Filing Date: 2015-07-14
Classification: G01B,G01N

Abstract:
1. An observation device comprising: a light source which outputs light; an interference optical system which branches the light output from the light source into two to output as a first branched light and a second branched light, inputs a first reflected light generated due to the first branched light being reflected by a mirror, inputs a second reflected light generated due to the second branched light being reflected by a surface or an inside of an observation object, and causes the first reflected light and the second reflected light to interfere with each other to output an interference light; an imaging optical system which images the interference light output from the interference optical system; an image pickup unit which takes an image of an interference light figure imaged by the imaging optical system; optical path difference adjusting means for adjusting an optical path difference between an optical path length from the light source via a reference position of the observation object up to the image pickup unit and an optical path length from the light source via the mirror up to the image pickup unit; a control unit which controls an optical path difference adjusting operation by the optical path difference adjusting means such that the optical path difference becomes each target value in sequence; and an analyzing unit which determines a complex amplitude of the interference light figure taken as an image by the image pickup unit with a phase shift technique after the optical path difference is set to each target value in sequence by the optical path difference adjusting means, and determines an amount of change per certain time of a phase component of the second reflected light generated on the surface or the inside of the observation object on the basis of an absolute value of an amount of change per certain time of the determined complex amplitude and an absolute value of the complex amplitude.