An optical imaging method in an embodiment includes: a scanning step to scan each of a plurality of A-lines of an object with a signal light while alternately changing the phase difference between the signal light and a reference light to two preset phase differences a detection step to detect the interference light of the signal light passing through the A-line and the reference light and an imaging step to generate a complex interference spectrum based on the detection results of the interference lights corresponding to the plurality of A-lines sequentially obtained in the detection step according to the scanning, and form, based on the complex interference spectrum, the tomographic image along the arrangement of the plurality of A-lines in which a complex conjugate artifact is substantially removed.
