Affiliation:
1. Department of Physics and Institute of Electromagnetics and Acoustics College of Physical Science and Technology Xiamen University Xiamen 361005 China
2. Department of Electrical and Computer Engineering National University of Singapore Singapore 117583 Singapore
3. Department of Microelectronics and Integrated Circuit, School of Electronic Science and Engineering Xiamen University Xiamen 361005 China
4. Jiujiang Research Institute of Xiamen University Jiujiang 332000 China
Abstract
AbstractMuch 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.
Funder
National Key Research and Development Program of China
China Scholarship Council