Design and fabrication of a passive integrated polarization splitter on the generic InP platform

An integrated fully passive polarization beam splitter on the generic InP platform is designed and fabricated. The birefringence of the waveguide is the only effect which is used for the beam splitting mechanism. The device is based on an asymmetric Mach–Zehnder interferometer with a curved waveguide in the upper arm and a straight waveguide in the lower arm to introduce π phase differences between the transverse electric (TE) and transverse magnetic (TM) modes. Measurement results at the wavelength of 1.55 μm indicated a splitting ratio of 11 dB and 20 dB for TE and TM input light, respectively. Since the designed device is based on the standard deep and shallow waveguides on the InGaAsP–InP platform it can be monolithically integrated with active and passive components, without any extra fabrication steps.