2021/02/02 by Andreas Henkel, Maik Meudt, Henkel, Andreas +5
Engineering · Physics and Astronomy · #Bound state #Broadband #Excitation #FOS: Physical sciences #Optics #Optics (physics.optics) #Optoelectronics #Photonic Crystals and Applications #Photonic and Optical Devices #Photonic crystal #Photonics #Physics #Plasmonic and Surface Plasmon Research #Quantum mechanics #Refractive index #Wavelength #physics.optics
paper · pdf · doi:10.48550/arxiv.2102.01686
arxiv created 2021/02/02 · openalex publication_date 2021/02/02 · arxiv updated 2021/02/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The question of how to continuously manipulate a photonic system between a radiating state and a bound state is an important challenge in photonics, as its solution promises broad technological relevance for optical sensors, modulators, switches and displays. Existing approaches utilise the inherent wave-nature of electromagnetic fields to their advantage, and are commonly identified as bound states in the continuum (BICs), as they resemble singular bound states embedded in a band of radiating states. Although quasi-BICs have been demonstrated for numerous symmetric periodic photonic crystals, their existence so far has been limited to narrow spectral ranges, and their application in switches or modulators needs large changes of the refractive index. Here, we show that the incidence of two guided symmetric substrate waves of opposite phase onto a symmetric periodic film waveguide enables the excitation of self-stabilising BICs which are electrically switchable in a broad optical range, with small changes of the refractive index. An experimental verification of the concept shows a switching contrast C=700 at a wavelength of 532 nm and C=1000 at a wavelength of 632.8 nm.