Patent ID: 7016052

Claim:
An apparatus for measuring characteristics of a hole, the apparatus comprising: at least one optical fiber capable of being introduced into the hole, wherein said optical fiber directs light radially toward a hole wall and receives light reflected off the hole wall; a light source for providing light to said optical fiber; an optical receiver for receiving light from said optical fiber that has reflected off the hole wall and been received by said optical fiber, said optical receiver also adapted to measure the intensity of the light reflected off the hole wall so as to permit different materials to be distinguished; and a movable mirror and an optical splitter for directing light from said light source both to said movable mirror and said optical fiber, wherein said optical receiver measures the intensity of the light reflected off the hole wall and the intensity of the light reflected off the mirror as the mirror is translated in order to determine the distance from a distal end of said optical fiber to the hole wall.