Department of Physics and Astronomy and LENS, University of Florence, via Sansone 1, I-50019, Sesto Fiorentino (FI), Italy.
Department of Applied Physics and Institute for Photonic Integration, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands.
Adv Mater. 2019 Mar;31(12):e1807274. doi: 10.1002/adma.201807274. Epub 2019 Feb 4.
Random dielectrics defines a class of non-absorbing materials where the index of refraction is randomly arranged in space. Whenever the transport mean free path is sufficiently small, light can be confined in modes with very small volume. Random photonic modes have been investigated for their basic physical insights, such as Anderson localization, and recently several applications have been envisioned in the field of renewable energies, telecommunications, and quantum electrodynamics. An advantage for optoelectronics and quantum source integration offered by random systems is their high density of photonic modes, which span a large range of spectral resonances and spatial distributions, thus increasing the probability to match randomly distributed emitters. Conversely, the main disadvantage is the lack of deterministic engineering of one or more of the many random photonic modes achieved. This issue is solved by demonstrating the capability to electrically and mechanically control the random modes at telecom wavelengths in a 2D double membrane system. Very large and reversible mode tuning (up to 50 nm), both toward shorter or longer wavelength, is obtained for random modes with modal volumes of the order of few tens of (λ/n) .
随机介质定义了一类非吸收材料，其折射率在空间中随机排列。只要传输平均自由程足够小，光就可以被限制在具有非常小体积的模式中。随机光子模式因其基本物理洞察力而受到研究，例如安德森局域化，最近在可再生能源、电信和量子电动力学领域设想了几种应用。随机系统为光电和量子源集成提供的一个优势是它们具有高密度的光子模式，这些模式跨越了很大的光谱共振和空间分布范围，从而增加了与随机分布的发射器匹配的概率。相反，主要的缺点是缺乏对许多随机光子模式中的一个或多个模式的确定性工程设计。通过证明在 2D 双膜系统中以电信波长对随机模式进行电和机械控制的能力，可以解决这个问题。对于模态体积约为几十（λ/n）的随机模式，可以获得非常大且可反转的模式调谐（高达 50nm），无论是向短波长还是长波长调谐。
