Apparatus and method for determining the orientation of axes of birefringence in an optical fiber.

摘要

An apparauts and process for accurate alignament of the birefrigent axes of circular fibers, and differentiation between the fast and slow axes utilizing an externally induced stress birefringence to change the orientation and magnitude of the natural fiber birefringence at a selected point along the length of the fiber (24) is disclosed. The apparatus comprises a light source (60) for supplying polarized light to the fiber (24), means (66, 68) for inducing stress to the fiber at that point in a variable direction and means (78) for monitoring the effect on the light as that direction is varied. A measurement of coupling from one polarization mode of the fiber to the othe as the axis of induced stress is changed provides an accurate determination of the lacation of the birefringent axes of the fiber (24).