Growth of polarisation crosstalk along a silica-based optical waveguide

The authors report the length dependence of polarisation crosstalk for a 10 m long silica-based waveguide in which the total polarisation crosstalk is 8.9×10^-3. This is achieved by numerically integrating the coupling strength obtained by using low coherence interference between excited and orthogonally coupled light waves along the length of the waveguide. A comparison of the measured and theoretical crosstalk curves leads to confirmation that the bends in the waveguide are the main origin of the crosstalk. The polarisation crosstalk per bent section is 4.7×10^-5