20110063605 | METHOD OF TESTING A PASSIVE OPTICAL ELEMENT - A passive optical element defining an optical propagation path is tested by coupling a first end of a first buffer fiber to an input of the optical propagation path and coupling a second end of the buffer fiber to an optical time domain reflectometer (OTDR). The OTDR launches optical radiation into the first buffer fiber via the second end thereof, measures power level of return light received at the OTDR via the second end of the first buffer fiber, and creates a first OTDR signature representing power level of return light as a function of distance from the second end of the first buffer fiber. The OTDR selects a first marker point by applying data reduction to at least a portion of a segment of the first OTDR signature corresponding to the first buffer fiber, selects a second marker point downstream of the input of the optical propagation path, and calculates a first power difference value as difference between a power level at the first marker point and a power level at the second marker point. | 03-17-2011 |