Design and Implementation of a Polarization Qubit Discriminator in Integrated Photonic Quantum Gates

Quantum state measurement is necessary in optical quantum computation. We present a polarizing beam splitter (PBS) based on planar lightwave circuit (PLC) which acts asquantum state discriminator in quantum computation. A directional coupler has been used for implementation of thisdevice. We use lithium niobate as a wafer material and Ti:LiNbO3 for waveguide. The length and spacing of this directional coupler have been designed such that eachpolarization is routed in specific output. The proposed device has one input and two outputs. If polarization of the input photon is horizontal, then this photon will appear in output 1, otherwise if the input photon has vertical polarization, it appears in output 2. Designed polarizing beam splitter has length of 22 mm and width of 60 micron.

Keywords:

Quantum Computation , cluster states , planer light wave circuits , polarizing beam splitter , directional coupler