A dual-way directional surface-plasmon-polaritons launcher based on asymmetric slanted nanoslits

Abstract

2014): A dual-way directional surface-plasmon-polaritons launcher based on asymmetric slanted nanoslits, Journal of Modern Optics,We theoretically design a device composed of two asymmetric slanted nanoslits to achieve the directionality of surface plasmon polaritons (SPPs). With proper inclination of the two slits, the desirable relative phase delay can be obtained. When the structure is illuminated by normal incident light, the SPPs can be controlled to deflect the specific direction due to light interference. The SPPs can be altered to the opposite direction when the illuminating light is changed inversely. We develop another way to tailor the relative phase delay by choosing the specific effective index for each slanted slit. In order to acquire higher directional excitation efficiency, our designs have been extended to periodic structures with the pairs of slanting slits. The finite element method is carried on to verify our designs. The simulations show that the best proportion of the SPP field intensity along two opposite directions reaches to around 30.

Surface Plasmon Polariton Unidirectional Nano-Launcher Based on the Strong Coupling Effects in an Asymmetric Optical Slot Nanoantenna Pair

“…Recently, a number of plasmonic structures have been proposed for SPP coupling. By employing asymmetric structures [8][9][10][11][12][13][14][15][16], incident angles [17], or positions [18], unidirectional SPP launching has been achieved. Interference effects between two or more SPP sources are commonly used for unidirectional SPP launching.…”

Refractive Index Sensor Based on a Metal-Insulator-Metal Bus Waveguide Coupled with a U-Shaped Ring Resonator

“…When the size of a specific nanostructure is reached, SPPs can break through the limited conventional diffraction and control light on the nanoscale [ 3 , 4 ]. SPPs have three characteristics: low dimension and high intensity and subwavelength, which make them a good energy and information carrier, and their ability to combine subwavelengths can be used to make various optical devices [ 5 ], such as wavelength demultiplexers [ 6 , 7 ], plasmonic filters [ 8 , 9 ], logic gates [ 10 ], couplers [ 11 ], and sensors [ 12 , 13 ].…”

Highly Efficient Excitation of Surface Plasmons Using a Si Gable Tip

“…However, if SPP‐based devices are to be routinely included in the design of current integrated optical devices, an efficient and compact excitation scheme of the SPP in an integrated setting is required. There have been a number of advanced SPP excitation schemes proposed in the literature let alone the most commonly used SPP excitation schemes like the prism coupling in Otto or Kretschmann configurations and metallic grating coupling . Liu et al.…”

“…There have been a number of advanced SPP excitation schemes proposed in the literature let alone the most commonly used SPP excitation schemes like the prism coupling in Otto or Kretschmann configurations and metallic grating coupling. [9][10][11][12][13][14][15][16] Liu et al have demonstrated a high DOI: 10.1002/lpor.201700009 efficiency dual layer grating SPP excitation mechanism for a gold/air interface [16] ; whereas, Pors et al have demonstrated 1D and 2D gap resonators for directional excitation of SPP modes. [9] Such couplers are highly efficient, but are typically narrow in bandwidth and require out-of-plane bulky and angle sensitive setup.…”

“…Thus SPPs have found applications in many emerging areas of nanophotonics such as integrated optics [3,4], field enhancement [5], sensing [6] and imaging [7,8]. Advancements have been made to improve the directionality and controllability of an excited SPP mode [9][10][11][12][13]. Similarly an efficient excitation of the SPP mode from the source is of equal importance for nanophotonic applications since SPP modes are inherently lossy due to the resistive loss of the metal.…”