【摘 要】
:
We demonstrate a photonic analog of twisted bilayer graphene that has ultra-flat photonic bands and exhibits extreme slow-light behavior. Our twisted bilayer photonic device, which has an operating wavelength in the C-band of the telecom window, uses two
【机 构】
:
School of Engineering and Applied Sciences,Harvard University,Cambridge,MA 02138,USA;Brown Theoretic
论文部分内容阅读
We demonstrate a photonic analog of twisted bilayer graphene that has ultra-flat photonic bands and exhibits extreme slow-light behavior. Our twisted bilayer photonic device, which has an operating wavelength in the C-band of the telecom window, uses two crystalline silicon photonic crystal slabs separated by a methyl methacrylate tunneling layer. We numerically determine the magic angle using a finite-element method and the corresponding photonic band structure, which exhibits a flat band over the entire Brillouin zone. This flat band causes the group velocity to approach zero and introduces light localization, which enhances the electromagnetic field at the expense of bandwidth. Using our original plane-wave continuum model, we find that the photonic system has a larger band asymmetry. The band structure can easily be engineered by adjusting the device geometry, giving significant freedom in the design of devices. Our work provides a fundamental understanding of the photonic properties of twisted bilayer photonic crystals and opens the door to the nanoscale-based enhancement of nonlinear effects.
其他文献
Broadband metamaterials absorbers with high absorption, ultrathin thickness and easy configurations are in great demand for many potential applications. In this paper, we first analyse the coupling resonances in a Ti/Ge/Ti three-layer absorber, which can
Carbon dots (CDs) have received immense attention in the last decade because they are easy-to-prepare, nontoxic, and tailorable carbon-based fluorescent nanomaterials. CDs can be categorized into three subgroups based on their morphology and chemical stru
Optical microcavities play a significant role in the study of classical and quantum chaos. To date, most experimental explorations of their internal wave dynamics have focused on the properties of their inputs and outputs, without directly interrogating t
Optical coherence tomography (OCT) is a widely used non-invasive biomedical imaging modality that can rapidly provide volumetric images of samples. Here, we present a deep learning-based image reconstruction framework that can generate swept-source OCT (S
Short Bio: Dr., Prof. John Dudley received his Ph.D. from the University of Auckland and is currently a Pro-fessor at the University of Franche-Comté in Besan?on, France. He is a Fellow of OSA, SPIE, IEEE, EOS, and an Honorary Fellow of the Royal Society
A nonlinear hologram enables to record the amplitude and phase of a waveform by spatially modulating the second order nonlinear coefficient, so that when a pump laser illuminates it, this waveform is reconstructed at the second harmonic frequency. The con
The intra-cavity electro-magnetic field distribution in a microdisk resonator can be visualised by inducing a phase shift via a scanning probe beam.
The apparent increase in hormone-induced cancers and disorders of the reproductive tract has led to a growing demand for new technologies capable of detecting endocrine disruptors. However, a long-lasting challenge unaddressed is how to achieve ultrahigh
Highly sensitive force measurements of a single microscopic particle with femto-Newton sensitivity have remained elusive owing to the existence of fundamental thermal noise. Now, researchers have proposed an optically controlled hydrodynamic manipulation
Photobiomodulation, by utilizing low-power light in the visible and near-infrared spectra to trigger biological responses in cells and tissues, has been considered as a possible therapeutic strategy for Alzheimer\'s disease (AD), while its specific mech