1. An optical image measuring device, comprising: an optical system configured to split a low-coherence light into a signal light and a reference light, split an optical path of the reference light into a plurality of optical paths having different optical path lengths to split the reference light into a plurality of reference lights, make the plurality of reference lights propagated through the plurality of optical paths, respectively, interfere with the signal light propagated through a measured object, and generate an interference light that reflects a morphology in each of a plurality of depth positions of the measured object; a detector configured to detect the generated interference light to generate a detection signal; an image forming part configured to form a plurality of tomographic images each representing the morphology of the measured object in a corresponding position among the plurality of depth positions based on the generated detection signal; and an analyzer configured to analyze the plurality of tomographic images to obtain a predetermined physical quantity of the measured object.