Double bi-material cantilever structures for complex surface plasmon modulation

Complex-amplitude modulation of surface waves based on a metasurface coupler

Simultaneous and independent modulation of the amplitude and phase of surface waves (SWs) is critical in photonics and plasmonics. Here, we propose a method for flexible complex-amplitude modulation of SWs based on a metasurface coupler. Benefiting from the full range complex-amplitude modulation ability of the meta-atoms over the transmitted field, the coupler can convert the incident wave into a driven surface wave (DSW) with an arbitrary combination of amplitude and initial phase. By placing a dielectric waveguide that supports guided SWs below the coupler, the DSWs can resonantly couple to SWs while preserving complex-amplitude modulation. The proposed scheme provides a practical way for freely tailoring the phase and amplitude profiles of SWs wavefronts. As verification, meta-devices for normal and deflected SW Airy beam generation and SW dual focusing are designed and characterized in the microwave regime. Our findings may stimulate various advanced surface optical meta-devices.

Mechanically-Tunable Photonic Devices with On-Chip Integrated MEMS/NEMS Actuators

This article reviews mechanically-tunable photonic devices with on-chip integrated MEMS/NEMS actuators. With related reports mostly published within the last decade, this review focuses on the tuning mechanisms of various passive silicon photonic devices, including tunable waveguides, couplers, ring/disk resonators, and photonic crystal cavities, and their results are selectively elaborated upon and compared. Applications of the mechanisms are also discussed. Future development of mechanically-tunable photonics is considered and one possible approach is based on plasmonics, which can confine light energy in the nano-scale space. Optomechanics is another innovation, derived from the strong coupling of optical and mechanical degrees of freedom. State-of-the-art studies of mechanically-tunable plasmonics and on-chip optomechanics are also selectively reviewed.