Lee June Sang, Farmakidis Nikolaos, Aggarwal Samarth, Dong Bowei, Zhou Wen, Pernice Wolfram H P, Bhaskaran Harish
Department of Materials, University of Oxford, Oxford, UK.
Kirchhoff-Institute for Physics, Heidelberg University, Heidelberg, Germany.
Nanophotonics. 2024 Jan 9;13(12):2117-2125. doi: 10.1515/nanoph-2023-0651. eCollection 2024 May.
Fast modulation of optical signals that carry multidimensional information in the form of wavelength, phase or polarization has fueled an explosion of interest in integrated photonics. This interest however masks a significant challenge which is that independent modulation of multi-wavelength carrier signals in a single waveguide is not trivial. Such challenge is attributed to the longitudinal direction of guided-mode propagation, limiting the spatial separation and modulation of electric-field. Here, we overcome this using a single photonic element that utilizes active coherent (near) perfect absorption. We make use of standing wave patterns to exploit the spatial-degrees-of-freedom of in-plane modes and individually address elements according to their mode number. By combining the concept of coherent absorption in spatio-spectral domain with active phase-change nanoantennas, we engineer and test an integrated, reconfigurable and multi-spectral modulator operating within a single element. Our approach demonstrates for the first time, a non-volatile, wavelength-addressable element, providing a pathway for exploring the tunable capabilities in both spatial and spectral domains of coherent nanophotonics.
对以波长、相位或偏振形式承载多维信息的光信号进行快速调制，激发了人们对集成光子学的极大兴趣。然而，这种兴趣掩盖了一个重大挑战，即如何在单个波导中对多波长载波信号进行独立调制并非易事。这一挑战归因于导模传播的纵向方向，它限制了电场的空间分离和调制。在此，我们通过使用一个利用有源相干（近）完美吸收的单一光子元件克服了这一问题。我们利用驻波模式来开发面内模式的空间自由度，并根据其模式编号分别处理各个元件。通过将空间光谱域中的相干吸收概念与有源相变纳米天线相结合，我们设计并测试了一种在单个元件内运行的集成、可重构和多光谱调制器。我们的方法首次展示了一种非易失性、波长可寻址元件，为探索相干纳米光子学在空间和光谱域的可调谐能力提供了一条途径。
