Fabrication and characterization of optimized corner-cut square microresonators

In this paper we report the fabrication and characterization of waveguide coupled square resonators with modified corners, in particular the corner-cut square resonator. We employ rigorous FDTD analysis to identify an optimal corner-cut length and compare this with our experimental findings. Two-and three dimensional FDTD analysis is also used to optimize the coupling gap and the width of the coupling waveguide. Fabrication of the square microresonators on silicon-on-insulators by conventional E-beam lithography and dry etching techniques will be discussed in detail. The characterization of these corner-cut square microresonators shows good performance and excellent agreement with the rigorous electromagnetic simulations. (C) 2008 Optical Society of America