Patent ID: 7428052

Claim:
An optical tomographic apparatus capable of providing a tomographic image of a subject, which comprises: a probe comprising: a reflecting mirror; a semitransparent mirror; and an object optical system in this order from a side of a fore-end portion of the probe; a light source that emits light having low coherence; and an interferometer that: divides the light emitted from the light source into two lights; irradiates the subject with one of the two lights; irradiates a reference face with the other of the two lights; combines reference light reflected from the reference face and subject light reflected from the subject so as to obtain interference light; and photoelectrically converts the interference light into a signal so as to enable to output the signal, wherein the interferometer comprises said probe that emits irradiating light to the subject and receives the subject light reflected from the subject, and the semitransparent mirror of the probe that separates the irradiating light into first irradiating light and second irradiating light, the first irradiating light is reflected by the semitransparent mirror so that the probe emits the first irradiating light in a first side direction of the probe and the second irradiating light transmits through the semitransparent mirror to the reflecting mirror, is reflected by the reflecting mirror to return again to the semitransparent mirror, and is reflected by the semitransparent mirror so that the probe emits the second irradiating light in a second side direction of the probe, the second side direction being a direction inverse to the first side direction.