All fiber 2 x 2 polarization insensitive switch

We report the development of a polarization insensitive all fiber 2×2 acoustooptic switch based on twisting the waist of a null taper coupler. The polarization insensitivity is better than 0.2 dB, the device requires a drive power of <1 mW, and exhibits a switching time of <50 μs and insertion loss of 0.1 dB.