AI 中文总结
本研究提出新型基于声光调制器（AOM）的控制系统，结合反馈与前馈控制并优化光路，实现兆赫级超低声噪的高功率激光强度控制，适用于光晶格超冷原子实验等场景。
AI 中文摘要
物理学多个领域的广泛应用需要兼具低相对强度噪声、可同步动态调控光强的高功率激光源。声光调制器（AOM）因驱动电路简单、自由空间中可承受高光学功率，被广泛用于主动功率稳定与调控。但AOM晶体内声波的传播速度较慢，通常将其控制带宽限制在数百千赫。本研究提出一种新型基于AOM的控制系统，可将高功率激光的强度噪声显著抑制至兆赫级。通过将两个标准反馈回路与一个前馈控制支路结合，并优化AOM晶体内的光路，实现了低至-155 dB·Hz⁻¹的超低相对强度噪声水平，即使在数百千赫下也能达到该指标。研究结果适用于需要傅里叶频率达兆赫级的超低强度噪声的应用，如光晶格超冷原子实验。
英文摘要
High-power laser sources that exhibit low relative intensity noise and allow simultaneous dynamic control of their light level are required for a broad range of applications in various fields of physics. Acousto-optic modulators (AOMs) are widely used for active power stabilization and regulation due to their simple drive electronics requirements and high optical power handling capability in free-space. However, the rather slow propagation speed of the sound wave within the AOM crystal typically limits their control bandwidth to a few hundred kHz. In this work, we present a novel AOM-based control system that is capable of significantly suppressing intensity noise of high-power lasers up to the MHz range. By combining two standard feedback loops with one feedforward control branch and optimizing the beam path in the AOM crystal, ultra-low relative intensity noise levels down to $-155\, \text{dB}\,\text{Hz}^{-1}$ even at several hundred kHz are achieved. Our results are relevant for applications that require ultra-low intensity noise at Fourier frequencies up to the MHz range, such as optical lattice experiments with light ultracold atoms.
