DEVICE AND METHOD FOR REDUCING POLARIZATION DEPENDENT LOSS IN AN OPTICAL MONITOR DEVICE

摘要

A device and method for monitoring characteristics of optical signals in an optical telecommunications system (500) are disclosed. The device includes a wedge of birefringent material (400a) disposed in an optical path of the device. The thickness of the wedge of birefringent material varies in at least one dimension along the direction of propagation of an optical beam passing through the device. The variation in wedge thickness causes the polarization state of the optical beam to be a function of position along the wedge. The composite energy in the optical beam appears to be formed of two orthogonal polarization components with no phase relationship to each other. If the two orthogonal polarization components of the optical beam are disposed at a predetermined angle relative to the principal efficiency axes of the device, such as approximately 45 degrees, the polarization dependent loss of the device is substantially reduced.