Fabrication-tolerant integrated polarisation splitter based on cascaded Mach - Zehnder interferometers

We report a fabrication-tolerant polarisation splitter based on cascaded Mach - Zehnder interferometers. This configuration enables a factor of 2 - 3 increase (at the level) in the tolerance to the phase difference in comparison with a single interferometer. As an example, we present numerical simulation of a splitter with a centre wavelength of , based on a planar waveguide from . The permissible channel waveguide width deviation from calculation results ( extinction coefficient bandwidth) is for the TE polarisation and for the TM polarisation.