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Much effort in the past few years has been made in tunnelling, however, no work has been reported so far on how to maintain the maximum tunnelling of complex optical fields in waveguides, due to the limitations of existing physical mechanisms. Here, a new paradigm is presented for realizing anomalous wave tunnelling through a general effective double‐barrier model constructed by dispersion engineering, while preserving mode information. The observed tunnelling mechanism is corroborated well by experimental results in the microwave realm. Specifically, evanescent waves bridge the gap between external space and potential well, allowing us to modulate the leaky modes within the potential well and thus achieve multiple resonant tunnelling. Due to the constant phase difference between adjacent maximum tunnelling, such mechanism broadens the potential of binary integrated devices. For example, assembling the tunnelling unit into arrays straightforwardly alleviates the trade‐off dilemma between diffraction law and cut‐off frequency. In addition, this approach provides an ideal toolbox for achieving multifunctional tunnelling across waveguide modes of various orders or polarizations, which can boost various applications in optical filters, tunneling lasers, optical switching, and sensing. [ABSTRACT FROM AUTHOR]

By combining transformation optics and van der Waals layered materials, an invisibility concentrator with a thin layer of α-MoO3 wrapping around a cylinder is proposed. It inherits the effects of invisibility and energy concentration at Fabry–Pérot resonance frequencies, with tiny scattering. Due to the natural in-plane hyperbolicity in α-MoO3, the challenges of experimental complexity and infinite dielectric constant can be resolved perfectly. Through analytical calculation and numerical simulations, the relevant functionalities including invisibility, energy concentration and illusion effect of the designed device are confirmed, which provides guidelines for the subsequent experimental verification in future.

By combining transformation optics and van der Waals layered materials, an invisibility concentrator with a thin layer of α-MoO3 wrapping around a cylinder is proposed. It inherits the effects of invisibility and energy concentration at Fabry–Pérot resonance frequencies, with tiny scattering. Due to the natural in-plane hyperbolicity in α-MoO3, the challenges of experimental complexity and infinite dielectric constant can be resolved perfectly. Through analytical calculation and numerical simulations, the relevant functionalities including invisibility, energy concentration and illusion effect of the designed device are confirmed, which provides guidelines for the subsequent experimental verification in future. [ABSTRACT FROM AUTHOR]