372048.fig.001
Figure 1: (a) Schematic of a MDM plasmonic waveguide side-coupled to two MDM stub resonators. (b) Schematic defining the reflection coefficient 𝑟 1 and transmission coefficients 𝑡 1 , 𝑡 2 , 𝑡 3 when the fundamental TM mode of the MDM waveguide is incident at a waveguide crossing. Note that 𝑡 2 = 𝑡 3 due to symmetry. (c) Schematic defining the reflection coefficient 𝑟 2 of the fundamental TM mode of the MDM waveguide at the boundary of a short-circuited MDM waveguide. (d) Transmission spectra for the structure of (a) calculated using FDFD (circles), transmission line theory (solid blue line), and scattering matrix theory (solid red line) for a silver-air structure with 𝑤 = 5 0  nm. Also shown are the reflection (solid green line) and absorption (solid cyan line) spectra calculated using FDFD. Results are shown for 𝐿 1 = 3 6 0  nm, 𝐿 2 = 1 6 0  nm. ((e)–(g)) Magnetic field profiles for the structure of (a) for 𝐿 1 = 3 6 0  nm, 𝐿 2 = 1 6 0  nm, 𝑤 = 5 0  nm at 𝑓 = 1 4 3 , 299, 194 THz, when the fundamental TM mode of the MDM waveguide is incident from the left.