Defective T-junction Composite Waveguides with Point Vacancies in Different Positions

A standard T-junction composite waveguide comprises a ridge structure and several layers of square-lattice dielectric cylinders around the intersection. A vacancy defect may arise if one cylinder is missing during imperfect fabrication process. In this work, the defective T-junc- tion composite waveguides with point vacancies in different positions are investigated. And their respective optical transmissions are obtained by the finite-difference time-domain (FDTD) simulation.