Optical tomographic imaging method and optical tomographic imaging apparatus

An optical tomographic imaging method for picking up a cross-sectional image of an object, by guiding a plurality of measurement lights to the object, synthetically combining the plurality of return lights reflected or scattered by the object with the plurality of corresponding reference lights by means of a light-combining unit, and detecting interference lights,

• the method comprising:
• a step of scanning a predetermined region of the object with spots of the plurality of measurement lights in the same direction by way of a scanning optical system, the predetermined region having a length in a direction perpendicular to the scanning direction, such that the length is smaller than the sum of diameters of the spots, to thereby irradiate different positions of the object with different spots of the plurality of measurement lights by way of an irradiation optical system;
• a step of detecting interference signals formed by the plurality of return lights from the different positions of the object and the plurality of corresponding reference lights;
• and
• a step of executing an arithmetic process on the detected interference signals based on a displacement amount between different spot positions, using interference signals corresponding to at least two of the spot positions out of the interference signals corresponding to the respective spot positions, to thereby improve the signal-to-noise ratio.