Opt Lett. 2018 Jul 15;43(14):3333-3336. doi: 10.1364/OL.43.003333.
The digital optical phase conjugation (DOPC) technique is being actively developed for optical focusing and imaging through or inside complex media. Due to its time-reversal nature, DOPC has been exploited to regenerate different intensity targets. However, whether the targets with three-dimensional information through complex media could be recovered has not been experimentally demonstrated, to the best of our knowledge. Here, we present a method to regenerate structured laser beams based on DOPC. Although only the phase of the original scattered wave is time reversed, the reconstruction of a quasi-Bessel beam and vortex beams through a multimode fiber (MMF) is demonstrated. The regenerated quasi-Bessel beam shows the features of sub-diffraction focusing and a longer depth of field with respect to a Gaussian beam. Moreover, the reconstruction of vortex beams shows the fidelity of DOPC both in amplitude and phase, which is demonstrated for the first time, to the best of our knowledge. We also prove that the reconstruction results of DOPC through the MMF are indeed phase conjugate to the original targets. We expect that these results could be useful in super-resolution imaging and optical micromanipulation through complex media, and further pave the way for achieving three-dimensional imaging based on DOPC.
数字光相位共轭 (DOPC) 技术正被积极开发用于通过或在复杂介质内部进行光学聚焦和成像。由于其时间反转的性质，DOPC 已被用于再生不同强度的目标。然而，据我们所知，通过复杂介质的具有三维信息的目标是否可以被恢复，尚未经过实验验证。在这里，我们提出了一种基于 DOPC 来再生结构激光光束的方法。虽然只反转了原始散射波的相位，但通过多模光纤 (MMF) 演示了准贝塞尔光束和涡旋光束的重建。与高斯光束相比，再生的准贝塞尔光束具有亚衍射聚焦和更长景深的特点。此外，我们还首次证明了 DOPC 对振幅和相位的重建具有保真度，这是据我们所知的首次证明。我们还证明，通过 MMF 的 DOPC 的重建结果确实与原始目标是相位共轭的。我们期望这些结果可用于通过复杂介质进行超分辨率成像和光学微操纵，并进一步为基于 DOPC 的三维成像铺平道路。
