Experimental study of transversal-stress-induced polarization crosstalk behaviors in polarization maintaining fibers

For the first time, we experimentally study the transversal-stress (T-stress) induced polarization crosstalk behaviors in polarization maintaining fibers (PMFs) including the linearity, sensitivity, response time and recovery time, using a distributed polarization crosstalk analysis (DPXA) system. Using two Panda PMFs with or without polyacrylate buffer coating and one Bow-tie PMF with golden polyimide coating as experimental samples, we find that: I) the polarization crosstalk can be highly linear with the T-stress for PMFs no matter with or without coating; II) the polyacrylate coating can reduce the crosstalk sensitivity of naked PMFs by more than hundreds of times, while replacing the polyacrylate coating with polyimide coating can increase the sensitivity by tens or even hundreds of times; III) the polyacrylate coating can induce a significant recovery time of crosstalk when a T-stress is removed after a long loading time compared with that in naked PMFs or golden PMF with polyimide coating, however the crosstalk response speed is too fast to be measured by the DPXA system. Additionally, we also find that the current polyimide coating technique still needs to be improved further to reduce the crosstalk base level. This work will be very useful for PMF-based distributed sensing applications and sensing PMF manufacturing.