Giant circular dichroic SHG behavior of double SP resonant chiral aluminum nanorod dimer structures

This paper reports on the giant circular dichroic second-harmonic generation (CD-SHG) behavior of double SP resonant chiral Al nanorod (AlNR) dimer structures. The two AlNRs are aligned in a straight line. It becomes chiral, when one of the AlNRs is shifted laterally from it. We obtained CD-SHG signals up to 0.5 for the corresponding amount of the shift. Additionally, the sign of the CD-SHG was reversed, when the sign of the shift was reversed. The amount of the CD-SHG was flexibly tunable by changing the amount of the shift, which was the uniqueness of the present chiral plasmonic nanostructure.