A polarization-actuated circulator for surface plasmon polaritons (SPPs) is experimentally realized in the optical regime for the first time. We demonstrate circulations of SPPs can be actuated either by linearly polarized excitation or by spin angular momenta carried by circular polarizations. Experimentally, a wide optical operational bandwidth of ~ 100 nm is achieved.
Dhruv’s Laser & Photonics Reviews paper
A simple plasmonic nanostructure is designed to allow polarization‐sensitive directional steering of surface plasmon polaritons (SPPs). Based on crossed Babinet‐inverted nanoantennas, steering of SPPs in the full first quadrant with high sensitivity to the linear polarization of the monochromatic exciting source is numerically and experimentally demonstrated. The same device could also function as a polarization‐driven power‐splitter.
Jamie’s SHG work published in Nano Letters
We demonstrate for the first time, second-harmonic generation (SHG) is allowed through the control of optical modal asymmetry rather than breaking the symmetry of material or geometry. Our idea is realized through a plasmonic two-wire transmission-line. As compared to other SHG using surface plasmon polaritons, our second-harmonic signal remains guided.
Talbot effect applied to orbital angular momenta
Talbot self-imaging is experimentally extended to cylindrical coordinate for the first time. Intensity petal repetition multiplication in the azimuthal angle of arbitrary multiplicative factor is demonstrated.
Jeff and Valley’s Nano Letters paper
We report the first creation of near-field orbital angular momentum excited by linearly polarized light that carries no optical angular momentum. The excited surface plasmons are measured using near-field scanning optical microscope and are found in excellent agreements to simulations quantitatively.