Patent ID: 7692797

Claim:
An optical tomography system for obtaining a tomographic image of an object to be measured comprising: a light source unit which emits low coherence light, a light dividing means which divides the low coherence light emitted from the light source unit into measuring light and reference light, a combining means which combines a reflected light from the object when the measuring light is projected onto the object and the reference light, an interference light detecting means which detects interference light of the reflected light and the reference light which have been combined by the combining means, and a tomographic image information obtaining means which obtains a tomographic image information of the object by carrying out frequency-analysis on the interference light detected by the interference light detecting means, and the interference light detecting means being able to be switched between a first detecting mode in which the interference light detecting means detects the interference light at a first wavelength resolution and a second detecting mode in which the interference light detecting means detects the interference light at a second wavelength resolution higher than the first wavelength resolution, wherein the interference light detecting means comprises a spectral means which spectrally divides the interference light, an optical sensor which detects the interference light divided by the spectral means and comprises a plurality of arranged photo-sensors, and a wavelength bandwidth switching means which switches the wavelength bandwidth of the interference light entering the optical sensor, the wavelength bandwidth switching means comprises a spectral angular width changing means which switches the spectral angular width of the interference light, and the wavelength bandwidth switching means comprises a plurality of diffraction gratings different in grating spaces and a diffraction grating selecting means which selectively disposes in a spectral dividing position where the interference light can be spectrally divided by one of the diffraction gratings.