High-efficiency and easy-to-fabricate integrated plasmonic grating couplers for the telecommunication wavelength range

The paper describes results of the numerical simulation and experimental characterization of plasmonic gratings and waveguides in the optical range of 1520–1630 nm. Gold structures were coated with a 630-nm thick tetraethylorthosilicate layer to achieve higher coupling efficiency for plasmonic gratings using lensed optical probes. We experimentally demonstrated gold input/output plasmonic gratings with an efficiency of about –3.8$\pm$0.2 dB per grating. The measured loss of the plasmonic mode propagating over the surface of the gold waveguide was 0.14$\pm$0.02 dB/$\mu$m. The work was carried out with the aim of studying integrated plasmonic structures for the development of a hybrid photonic-plasmonic integrated technology.