LAUSR

Plasmonic polarization multiplexers are becoming increasingly significant for the development of high-speed plasmonic interconnection with broad bandwidth. Here, we demonstrate that the symmetrical double-groove structure can act as a polarization multiplexer for broadband femtosecond surface plasmon polaritons (SPPs) by investigating the mode distributions with photoemission electron microscopy (PEEM). Experimental results show that the mode distribution of the SPPs field from the excitation of the double-groove structure is symmetrical when irradiated with p-polarized light, whereas the mode shows an anti-symmetric field distribution as a staggered, herringbone shape with s-polarized light excitation. Furthermore, the SPPs field distribution shows an asymmetrical mode when the double-groove is excited with a left or right-handed circular femtosecond laser pulse. The resulting PEEM images are supported by FDTD simulations. The proposed multiplexer is a promising building block for highly integrated optoelectronic integrated circuits.