Modal Analysis of Silicon Photonic Wire and TM-pass Nanowaveguide Polarizer

Modal analysis of silicon photonic wire is presented based on the full-vectorial eigenmode solution. Numerical results indicate that for different height and width of silicon photonic wire, there are five regions corresponding to different modal characteristics, namely, multimode region, singlemode region, single TE polarization region, single TM polarization region and cutoff region. Simple expressions are correspondingly proposed for the singlemode, single polarization mode and cut off conditions. With this modal analysis, a TM-pass nanowaveguide polarizer based on a tapered silicon nanowaveguide structure is proposed and demonstrated numerically.