Method for the rotational alignment of polarization-maintaining optical fibers and waveguides

A novel method has been developed for measuring the rotational angle of a fiber's or a waveguide's polarization axis with respect to a reference angle. The reference angle is the polarization axis of the measuring device. The method also gives the true polarization extinction ratio of the measured fiber or waveguide. The method is suitable for the characterization and rotational alignment of polarization-maintaining waveguides and fibers. In particular, the method can be used to rotationally align the fiber-waveguide interconnections during waveguide characterization. The measuring device is either a linear polarizer or a polarization splitter that is accurately rotated with respect to the device under test. According to the experiments with a polarization-maintaining fiber, the method is very easy and inexpensive to implement, and the angular accuracy can be better than 0.2 deg.