多艾里光束合成自聚焦光束的实验实现

摘要

Thus far, focusing a single beam and combining multi-optical Gaussian beams have become two major methods of locally en-hancing output laser intensity. In this paper, we propose a method of generating free space auto-focusing beams by combining multiple one-dimensional Airy beams. By employing split-step beam propagation method, auto-focusing beams generated by four and eight one-dimensional Airy beams are numerically simulated, and their intensity distributions are displayed from both transverse plane and side-view propagation. By utilizing a spatial light modulator and computer generated phase masks, these auto-focusing beams are experimentally demonstrated. Our experimental results accord well with the numerical simulations.%　　多光束合成和单光束聚焦一直是提高激光束功率和功率密度的两个重要方法。结合艾里光束在自由空间中沿弯曲路径传播的特性，从数值模拟和实验两个方面，研究了利用多个一维艾里光束合成自由空间自聚焦光束的方法，并对所得到的模拟和实验结果进行了对比。采用分步束传播法，分别模拟了由四个和八个一维艾里光束合成的自聚焦光束在自由空间中的传播过程，给出了自聚焦光束在传播过程中横向和纵向的光强分布和变化趋势。采用计算全息和空间光调制器技术实验，实现了多个一维艾里光束合成的自聚焦光束。实验中分别测量了四个和八个一维艾里光束合成的自聚焦光束的横向光强分布。实验结果和理论结果符合得较好。另外，为了进一步增大自聚焦光束的功率，可以增加参与合成的一维艾里光束的数量。同时，自聚焦光束的焦距可以通过调整各个一维艾里光束的相对位置进行调节。