Controlling Dual Fano Resonance Lineshapes Based on an Indirectly Coupled Double-Nanobeam-Cavity Photonic Molecule

We propose an ultracompact structure to efficiently achieve control and tuning of dual Fano resonance (DFR) lineshapes, in which a waveguide Fabry-Perot (FP) resonator is side-coupled to a double-nanobeam-cavity photonic molecule (FP-DNCPM). We theoretically and numerically demonstrate the transmission spectra of the FP-DNCPM coupled system can be converted between dual Lorentzian resonance (DLR) lineshapes and DFR lineshapes with arbitrary asymmetries by simply varying the phase shift in the waveguide FP resonator. We also show that our proposed system provides modulation capabilities for extinction ratio (ER), slope rate (SR), and group delay and we observe significant improvements in the performance of ER, SR, and slow light in the DFR lineshapes compared to the results obtained in the DLR lineshapes. We believe that our proposed structure holds significant potential as the candidate for multi-wavelength high-performance optical switches, modulators, slow light devices, and high-sensitivity sensors.