Advancements in photonic integration technology have enabled the effective excitation of simulated Brillouin scattering (SBS) on a single chip, boosting Brillouin-based applications such as microwave photonic signal processing, narrow-linewidth lasers, and optical sensing. However, on-chip circuits still require large pump power and centimeter-scale waveguide length to achieve a considerable Brillouin gain, making them both power-inefficient and challenging for integration. Here, we exploit the slow-light effect to significantly enhance SBS, presenting the first, to the best of our knowledge, demonstration of a slow-light Brillouin-active waveguide on the silicon-on-insulator (SOI) platform. By integrating a Bragg grating with a suspended ridge waveguide, a 2.1-fold enhancement of the forward Brillouin gain coefficient is observed in a 1.25 mm device. Furthermore, this device shows a Brillouin gain coefficient of 1,693 m⁻¹W⁻¹ and a mechanical quality factor of 1,080. The short waveguide length reduces susceptibility to inhomogeneous broadening, enabling the simultaneous achievement of a high Brillouin gain coefficient and a high mechanical quality factor. This approach introduces an additional dimension to enhance acousto-optic interaction efficiency in the SOI platform and holds significant potential for microwave photonic filters and high spatial resolution sensing.

中文翻译：

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具有集成布拉格光栅的慢光增强布里渊散射

光子集成技术的进步使得在单芯片上有效激发模拟布里渊散射（SBS）成为可能，从而促进了微波光子信号处理、窄线宽激光器和光学传感等基于布里渊的应用。然而，片上电路仍然需要大的泵浦功率和厘米级的波导长度才能实现相当大的布里渊增益，这使得它们的功率效率低下并且对集成具有挑战性。在这里，我们利用慢光效应来显着增强 SBS，据我们所知，首次在绝缘体上硅 (SOI) 平台上演示慢光布里渊有源波导。通过将布拉格光栅与悬浮脊波导集成，在 1.25 mm 器件中观察到前向布里渊增益系数增强了 2.1 倍。此外，该器件显示出1,693 m ^-1 W ^-1的布里渊增益系数和1,080的机械品质因数。短波导长度降低了对不均匀展宽的敏感性，从而能够同时实现高布里渊增益系数和高机械品质因数。这种方法引入了额外的维度来提高 SOI 平台中的声光相互作用效率，并在微波光子滤波器和高空间分辨率传感方面具有巨大的潜力。