Method and apparatus for measuring the distance of a discontinuity of a glass fiber from one end of the fiber

DETAILED DESCRIPTION The present invention is directed to a method and apparatus which enables measuring the distance of a discontinuity of a glass fiber from one end of the fiber.
To accomplish this task, the method and apparatus includes coupling a light pulse into the one end of the glass fiber, sensing a reflected light pulse from a discontinuity in the glass fiber as the reflected pulse leaves the one end, and measuring the time interval between coupling of the light pulse into the one end of the fiber and sensing the reflecting light pulse to determine the distance of the discontinuity from the one end.
The apparatus preferably utilizes a pulse laser for producing the light pulse, coupling means which includes a beam divider which may include optical means such as lenses for focusing the pulse into the one end and which coupling means will direct the reflected pulse received from one end to a means for sensing the light pulse.
The measuring is accomplised by means for measuring which includes a counter which receives a triggering pulse to start the counter and which counter is stopped by a pulse from the light sensing means when the sensing means senses a reflected pulse.
The laser is preferably a pulse laser which includes control means utilizing a pulse generator which may provide the triggering pulse to start the counter.