Measuring endoscope apparatus

1. A measuring endoscope apparatus comprising:

a light source unit provided with a low coherence light source that emits low coherence light;

a probe that illuminates an observation object with said low coherence light and that collects light reflected by said observation object; and

a single optical fiber that optically connects the probe and the light source unit; wherein

said light source unit further includes

a first low coherence light splitting part that splits the low coherence light emitted from the low coherence light source into a first low coherence light and a second low coherence light;

an optical path length adjustment part that adjusts the optical path length of said first low coherence light; and

an optical multiplexing part that multiplexes said first low coherence light, after it has passed through the optical path length adjustment part, and said second low coherence light onto said single optical fiber; and

said probe includes

a second low coherence light splitting part that splits said first low coherence light from light transmitted through said single optical fiber;

a low coherence light multiplexing part that multiplexes said second low coherence light after it has been reflected by said observation object and said first low coherence light split by said second low coherence light splitting part;

a lens that forms images using light returned from said observation object; and

an image detector that captures an interference pattern of the multiplexed low coherence lights.

2. The measuring endoscope apparatus according to claim 1 , and further comprising

an illumination light source that causes the probe to emit illumination light; wherein

said probe illuminates said observation object with the illumination light and with low coherence light; and

said lens forms images using said illumination light reflected by the observation object and using low coherence light reflected by the observation object.

3. The measuring endoscope apparatus according to claim 1 , wherein:

said low coherence light emitted from said low coherence light source is linearly polarized light;

said optical path length adjustment part includes

a movable mirror that is movable along the optical path of said first low coherence light and that reflects said first low coherence light so as to reverse the optical path thereof;

a polarizing member that rotates the polarization direction of said first low coherence light that is reflected by said movable mirror a total of 90 degrees; and

said second low coherence light splitting part is formed of a polarizing beam splitter that reflects one of said first low coherence light and said second low coherence light and that transmits the other.

4. The measuring endoscope apparatus according to claim 3 , wherein:

said low coherence light multiplexing part comprises

a polarizing beam splitter that forms said second low coherence light splitting part;

a mirror that reflects one of the low coherence lights split by said polarizing beam splitter;

a second polarizing member provided between said mirror and said polarizing beam splitter that rotates the polarization direction of said one low coherence light by a total of 90 degrees; and

a third polarizing member that makes the polarization directions the same for said first and second low coherence lights that are multiplexed by said polarizing beam splitter.