Abstract
In this work, we used finite-difference time-domain (FDTD) numerical analyses to find the optimized dimensions of plasmonics gap antenna arrays for near-infrared femtosecond laser which center wavelength is 1560nm. Total length of each gap antenna pair is designed for largest field enhancement at 1560nm. We find total length around 600nm to 640nm had best optical response for localized surface plasmon (LSP) field enhancement. High field enhancement caused by LSP give our large potential to induce nonlinear effect from our device. We used e-beam lithography (EBL) to fabricate the antenna. Each antenna array with different parameters covered 100um×100um area. Femtosecond pulse laser was used in experiment whose average power was 110mW, pulse duration was about 60 fs and with repetition rate 80MHz. Measurement data was recorded by camera and spectrometer in optical microscopy system. Finally, we compared experimental data with simulation to give our good promise for nonlinear effect generation by plasmonic gap antenna array.