A hybrid mode splitter for separation and excitation of photonic crystal odd and even modes using plasmonic waveguides

This study introduces a mode splitter through a novel coupling mechanism between photonic crystal waveguides and metal-insulator-metal plasmonic waveguides. Notably, the proposed structure demonstrates the capability to excite both odd and even modes within the photonic crystal waveguide. Numerical simulations of this structure were conducted using the finite difference time domain (FDTD) method. Our numerical analysis reveals an exceptional transmittance of 95 % at the waveguide intersection for the wavelength of 1550 nm. The successful coupling of plasmonic waveguides to photonic crystal waveguides unveils a vast array of opportunities for designing innovative devices that harness the synergistic potential arising from the distinctive characteristics of surface plasmons and photonic crystals. An inherent advantage of this design lies in its simple topology, enabling cost-effective and precise manufacturing processes. This device offers the ability to accurately separate and identify output modes. Additionally, we utilize this coupler in the design of a highly efficient power divider that not only achieves high transmittance but also provides adjustable control over the output power level.