Pseudo-depolarizer for interferometric fiber sensor applications

In fiber optic interferometric sensors, polarization noise and fading may occur due to environmental induced birefringence fluctuations. One way to overcome this problem is to depolarize the source light. For broadband sources such as light emitting diodes, the light can be easily depolarized by utilizing fiber implementations of conventional Lyot depolarizes. However, for highly coherent lasers, this approach is not viable. Several techniques for producing a depolarized source from coherent light have been demonstrated. However, they are only suitable for certain input polarization states, and often involve bulk optical components which may not be ideal for certain applications. In this paper, we report a simple all fiber depolarizer for coherent light which is suitable for any input polarization states.