Han Kyunghun, Lebrun Thomas W, Aksyuk Vladimir A
Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA.
Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA.
Optica. 2024;11(5). doi: 10.1364/OPTICA.516044.
In many physical systems, the interaction with an open environment leads to energy dissipation and reduced coherence, making it challenging to control these systems effectively. In the context of wave phenomena, such lossy interactions can be specifically controlled to isolate the system, a condition known as a bound-state-in-continuum (BIC). Despite the recent advances in engineered BICs for photonic waveguiding, practical implementations are still largely polarization- and geometry-specific, and the underlying principles remain to be systematically explored. Here, we theoretically and experimentally study low loss BIC photonic waveguiding within a two-layer heterogeneous electro-optically active integrated photonic platform. We show that coupling to the slab wave continuum can be selectively suppressed for guided modes with different polarizations and spatial structure. We demonstrate a low-loss same-polarization quasi-BIC guided mode enabling a high extinction Mach-Zehnder electro-optic amplitude modulator within a single SiN ridge waveguide integrated with an extended LiNbO slab layer. By elucidating the broad BIC waveguiding principles and demonstrating them in an industry-relevant photonic configuration, this work may inspire innovative approaches to photonic applications such as switching and filtering. The broader impact of this work extends beyond photonics, influencing research in other wave dynamics disciplines, including microwave and acoustics.
在许多物理系统中，与开放环境的相互作用会导致能量耗散和相干性降低，从而难以有效地控制这些系统。在波动现象的背景下，这种有损相互作用可以被特定地控制以隔离系统，这种状态被称为连续统中的束缚态（BIC）。尽管最近在用于光子波导的工程化BIC方面取得了进展，但实际应用在很大程度上仍然是特定于偏振和几何结构的，其 underlying principles仍有待系统地探索。在这里，我们在两层异质电光有源集成光子平台内对低损耗BIC光子波导进行了理论和实验研究。我们表明，对于具有不同偏振和空间结构的导模，可以选择性地抑制与平板波连续统的耦合。我们展示了一种低损耗同偏振准BIC导模，它在与扩展的LiNbO平板层集成的单个SiN脊形波导内实现了高消光马赫-曾德尔电光幅度调制器。通过阐明广泛的BIC波导原理并在与行业相关的光子配置中进行演示，这项工作可能会激发光子应用（如开关和滤波）的创新方法。这项工作的更广泛影响超出了光子学领域，影响了包括微波和声学在内的其他波动动力学学科的研究。
