Plasmonic wavelength-dependent optical switch

We design and experimentally demonstrate an optical switch based on the interference of plasmonic modes in whispering gallery mode (WGM) antennas. Simultaneous excitation of even and odd WGM modes, enabled by a small symmetry breaking via non-normal illumination, allows switching the plasmonic near field between opposite sides of the antenna, depending on the excitation wavelength used in a wavelength range of 60 nm centered around 790 nm. This proposed switching mechanism is experimentally demonstrated by combining photoemission electron microscopy (PEEM) with a tunable wavelength femtosecond laser source in the visible and infrared.

Automated summary

We have designed and experimentally demonstrated an optical switch that utilizes the interference of plasmonic modes in whispering gallery mode (WGM) antennas. By selectively exciting even and odd WGM modes through non-normal illumination, we are able to switch the plasmonic near field between opposite sides of the antenna within a wavelength range of 60 nm centered around 790 nm. This switching mechanism has been experimentally verified using photoemission electron microscopy (PEEM) and a tunable wavelength femtosecond laser source in the visible and infrared.