A High Extinction Ratio Polarization Beam Splitter With MMI Couplers on InP Substrate

Abstract

A high extinction ratio (ER) polarization beam splitter with three different multimode interference couplers on InP substrate was designed by a three-dimensional beam propagation method. Simulations show that the polarization ER (PER) is over 34 dB and internal loss is <;0.8 dB for both TE and TM polarizations. The PER imbalance between the two polarization states has been reduced to 22 dB. The total length of the device is <;950 μm. The effects of the width of the input port on the performance of the device are discussed in detail.