Tunable band-stop filters based on the strong coupling-like phenomenon in metal-insulator-metal cavities involving molecular J-aggregates

摘要

We investigate tunable band-stop filters based on the strong coupling-like phenomenon in metal-insulator-metal (MIM) cavities involving molecular J-aggregates sandwiched between two identical metal films. Finite difference time domain method is employed to well describe the strong coupling-like phenomenon, and the simulation results match well with the experiment results in the previous works: Eizner et al (2015 Nano Lett. 15 6215), Lin et al (2015 Nano Lett. 15 4699) and Zengin et al (2015 Phys. Rev. Lett. 114 157401). Molecular J-aggregates modify the transmission spectra of MIM structures, and the transmission spectra show flat stages with values close to zero due to the coupling between MIM cavities and molecular J-aggregates, which have potential applications as band-stop filters. The strong coupling-like phenomenon would be treated as hybridization modes between the non-radiative mode supported by the MIM structure and the radiative mode supported by molecular J-aggregates. The width of the stopband in the transmission spectrum generated by the strong coupling-like phenomenon is tuned by the size and the oscillation strength of molecular J-aggregates. The centre working wavelength of the band-stop filter would be modified by the resonant wavelength of molecular J-aggregates. Our structure is easily fabricated and has potential applications in integrated optics at nanoscales.