One dominant issue for micro-resonator filters has been polarization sensitivity due to the form asymmetry in nanophotonic waveguides. Differences in the filter�??s transmission intensity for TE and TM polarizations is attributed to the polarization dependent coupling. Complete power transfer in ultra-small directional couplers is demonstrated in agreement with simulations. Polarization dependence is simulated for waveguides of various widths, showing the presence of a critical width at which the propagation constants are equal for TE and TM modes. A design for polarization-independent and single-mode waveguides is discussed, along with implications for the applications of micro-resonators in general.
© 2003 Optical Society of AmericaPDF Article