A novel class of programmable integrated photonic circuits has emerged over the past years, strongly driven by approaches to tackle unsolved computing problems in the optical domain. Photonic neuromorphic and quantum computing are examples of optical systems implemented in complex photonic circuits, which are reconfigured before and during operation. However, a key building block to enable efficient reconfigurable optical network architectures is still missing: a non-volatile optical phase shifter. Here we demonstrate such an element—compatible with silicon photonics—based on the monolithic integration of BaTiO₃ thin films with silicon waveguides. By manipulating ferroelectric domains in BaTiO₃ with electrical control signals, we achieve analogue and non-volatile optical phase tuning with no absorption changes. We demonstrate an eight-level long-term-stable photonic device with non-destructive optical readout and switching energy as low as 4.6 pJ. With our results, an analogue non-volatile photonic element is added to the integrated photonics toolbox, enabling a new generation of power-efficient programmable photonic circuits.

过去几年出现了一类新颖的可编程集成光子电路，其主要受解决光学领域中未解决的计算问题的方法的推动。光子神经形态和量子计算是在复杂光子电路中实现的光学系统的示例，它们在操作之前和期间进行重新配置。然而，实现高效可重构光网络架构的关键构建块仍然缺失：非易失性光移相器。在这里，我们基于 BaTiO ₃薄膜与硅波导的单片集成演示了这种与硅光子学兼容的元件。通过操纵 BaTiO _{3中的铁电畴}通过电控制信号，我们实现了模拟和非易失性光学相位调谐，而没有吸收变化。我们展示了一种八级长期稳定光子器件，具有无损光学读出和低至 4.6 pJ 的开关能量。根据我们的结果，模拟非易失性光子元件被添加到集成光子学工具箱中，从而实现了新一代高能效可编程光子电路。