On-chip electro-optic frequency shifters and beam splitters
On-chip electro-optic frequency shifters and beam splitters
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DOI：
10.1038/s41586-021-03999-x
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发表时间：
2021-11-25
期刊：
影响因子：
64.8
通讯作者：
Loncar, Marko
中科院分区：
文献类型：
--
作者：
Hu, Yaowen;Yu, Mengjie;Loncar, Marko
有效的频移和分束对于广泛的应用是重要的，包括原子物理学（1，2）、微波光子学（3-6）、光通信（7，8）和光子量子计算（9-14）。然而，实现千兆赫兹级的频率偏移与高效率，低损耗和可调谐性，特别是使用一个微型和可扩展的设备是具有挑战性的，因为它需要有效的和可控的非线性过程。现有的基于声光（6，15 -17）、全光波混频（10，13，18 -22）和电光（23-27）的方法要么局限于低效率或低频率，要么体积庞大。此外，大多数方法不是双向的，这使得它们不适合频率分束器。在这里，我们展示了仅使用连续和单音微波控制的电光移频器。这是通过设计锂离子纳米光子学中超低损耗波导和谐振器中光学模式的态密度和耦合来实现的（28）。我们的器件由两个耦合环形谐振器组成，可提供高达28千兆赫的频移，片上转换效率约为90%。重要的是，这些器件可以重新配置为可调谐频域分束器。我们还展示了一个非阻塞和有效的交换两个频道之间的信息与设备之一。最后，我们提出并演示了一个级联频移方案，允许使用29.8千兆赫连续和单音微波信号的119.2千兆赫的移位。我们的器件可以成为未来高速和大规模经典信息处理器（7，29）以及新兴的频域光子量子计算机（9，11，14）的构建模块。在锂酸盐芯片中的光模式之间的耦合的工程使得能够实现仅使用连续和单音微波控制的可调谐、双向和低损耗电光频移器。
Efficient frequency shifting and beam splitting are important for a wide range of applications, including atomic physics(1,2), microwave photonics(3-6), optical communication(7,8) and photonic quantum computing(9-14). However, realizing gigahertz-scale frequency shifts with high efficiency, low loss and tunability-in particular using a miniature and scalable device-is challenging because it requires efficient and controllable nonlinear processes. Existing approaches based on acousto-optics(6,15-17), all-optical wave mixing(10,13,18-22) and electro-optics(23-27) are either limited to low efficiencies or frequencies, or are bulky. Furthermore, most approaches are not bi-directional, which renders them unsuitable for frequency beam splitters. Here we demonstrate electro-optic frequency shifters that are controlled using only continuous and single-tone microwaves. This is accomplished by engineering the density of states of, and coupling between, optical modes in ultralow-loss waveguides and resonators in lithium niobate nanophotonics(28). Our devices, consisting of two coupled ring-resonators, provide frequency shifts as high as 28 gigahertz with an on-chip conversion efficiency of approximately 90 per cent. Importantly, the devices can be reconfigured as tunable frequency-domain beam splitters. We also demonstrate a non-blocking and efficient swap of information between two frequency channels with one of the devices. Finally, we propose and demonstrate a scheme for cascaded frequency shifting that allows shifts of 119.2 gigahertz using a 29.8 gigahertz continuous and single-tone microwave signal. Our devices could become building blocks for future high-speed and large-scale classical information processors(7,29) as well as emerging frequency-domain photonic quantum computers(9,11,14).Engineering of the coupling between optical modes in a lithium niobate chip enables the realization of tunable, bi-directional and low-loss electro-optic frequency shifters controlled using only continuous and single-tone microwaves.