Patent ID: 7859682

Claim:
An optical interference apparatus for carrying out Fourier domain optical coherence tomography, comprising: a first beam splitter configured to generate a plurality of beams wherein interferograms are recorded simultaneously for a plurality of different focal depths within a substance to be examined, each interferogram being provided by one of the plurality of beams, the first beam splitter including: a reflecting surface; and a partially reflecting surface, wherein a received beam passes to the partially reflecting surface and a proportion of the beam passes through the partially reflecting surface to form a first beam and another proportion is reflected to the reflecting surface where it is reflected back to the partially reflecting surface and a proportion of the beam passes through the partially reflecting surface to form a second beam, the partially reflecting surface and the reflecting surface being disposed so that the first and second beam are displaced parallel to one another, further successive beams of the plurality of beams being provided by reflections and transmissions at the reflecting surface and the partially reflecting surface; and a probe configured to pass the plurality of beams to the substance to be examined at the plurality of different focal depths.