Fiber optic displacement sensor

摘要

An optical displacement sensor serves to sense variations in the displacement of a test article. This is achieved by securing a portion of the length of an optical fiber between two spaced points on a test article and then supplying a laser beam to propagate through the measurement fiber as well as through a reference fiber of the same length. Expansions and contractions of the test article causes changes in length of the measurement fiber. The light beams are recoupled to produce an interference pattern which varies as a function of variations in displacement of the test article.