Opt Express. 2022 Dec 5;30(25):44967-44982. doi: 10.1364/OE.476887.
Recently, a new type of abruptly autofocusing beam called circular Airyprime beam (CAPB) has been reported. Its abrupt autofocusing ability has been proven to be approximately seven times that of a circular Airy beam under the same conditions. Further improving the abrupt autofocusing ability of the CAPB without changing the beam parameters is a concern in optical research. In this study, we investigated the effect of introducing first- and second-order chirped factors on the abrupt autofocusing ability of the CAPB. When the positive first-order chirped factor was below the saturated chirped value, the abrupt autofocusing ability of the chirped CAPB was stronger and the focus position was smaller compared with those of the conventional CAPB. Regarding the abrupt autofocusing ability, there was an optimal value for the first-order chirped factor. At the optimal value, the abrupt autofocusing ability of the chirped CAPB was the strongest. On the other hand, a positive second-order chirped factor promoted the abrupt autofocusing ability of the CAPB and shortened the focus position. The introduction of such value was more effective than the introduction of a positive first-order chirped factor in promoting abrupt autofocusing of the CAPB. The abrupt autofocusing ability of the CAPB was further improved by combining the optimal first-order chirped factor and a positive second-order chirped factor. Finally, the chirped CAPB was experimentally generated, and the corresponding abrupt autofocusing behaviors were measured, validating the theoretical results. Overall, we provide an approach for improving abruptly autofocusing CAPBs.
最近,报道了一种新型的突然自聚焦光束,称为圆形艾里主光束(CAPB)。在相同条件下,其突然自聚焦能力被证明大约是圆形艾里光束的七倍。在不改变光束参数的情况下进一步提高 CAPB 的突然自聚焦能力是光学研究中的一个关注点。在这项研究中,我们研究了引入一阶和二阶啁啾因子对 CAPB 突然自聚焦能力的影响。当正一阶啁啾因子低于饱和啁啾值时,与常规 CAPB 相比,啁啾 CAPB 的突然自聚焦能力更强,焦点位置更小。关于突然自聚焦能力,一阶啁啾因子存在一个最佳值。在最佳值处,啁啾 CAPB 的突然自聚焦能力最强。另一方面,正二阶啁啾因子促进了 CAPB 的突然自聚焦能力并缩短了焦点位置。引入这种值比引入正一阶啁啾因子更有效地促进 CAPB 的突然自聚焦。通过结合最佳的一阶啁啾因子和正二阶啁啾因子,进一步提高了 CAPB 的突然自聚焦能力。最后,实验产生了啁啾 CAPB,并测量了相应的突然自聚焦行为,验证了理论结果。总的来说,我们提供了一种改进突然自聚焦 CAPB 的方法。