Birefringence of PM laser fibers with different structure

Polarization maintenance fiber with high birefringence is an important goal for the development of high power fiber lasers. There are different ways to achieve high birefringence, such as change shape of a fiber's core and apply stress to a fiber's core. In this paper, fibers with different ovality of elliptical core are fabricated and tested. On the other hand, stress type PM fibers are also made, including PANDA type fibers and bowtie type fibers. Their test results are compared and analyzed together with their structures. Generally, the bowtie type fibers has highest birefringence, while the PANDA fibers are with high birefringence and high production efficiency. Different application can choose different type of PM Laser fibers.