采用谱相位调制的方法,在理论上提出可调谐非傍轴自加速光束的产生方法,并通过实验对该理论进行验证。利用驻相近似和光学焦散线原理建立了谱相位与光束传输轨迹之间的数学模型。理论模拟和实验结果表明所提方法突破了传统傍轴近似的限制,产生了非傍轴自加速光束。这类轨迹灵活可控的自加速光束在光学微粒操纵、微粒运输和引导、超分辨成像等领域具有潜在的应用价值。

Herein, a method for generating tunable nonparaxial accelerating beams is proposed theoretically by spectral phase modulation and verified experimentally. The mathematical model of the relationship between spectral phase and beam propagation trajectory is established based on the stationary phase approximation and the principle of optical caustics. Theoretical simulations and experimental results show that the proposed method overcomes the limitations of conventional paraxial approximation, and nonparaxial accelerating beams are generated. Such accelerating beams with flexible and tunable trajectories have potential applications in the areas of optical particle manipulation, particle transport and guidance, and super-resolution imaging.