Experimental investigation on propagation characteristics of vortex beams in underwater turbulence with different salinity
doi: 10.37188/CO.EN.2021-0001
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摘要: 研究光束在海洋湍流中的传输特性尤为重要。为了更贴近实际情况，人工搭建了能控制水下湍流强度和盐度的装置来研究涡旋光束和高斯光束在水下湍流中的传输特性。结果表明：相比于未添加海盐的水下湍流，光束在增添海盐的水下湍流中传输光斑会更加弥散，光强会更弱。无论是强湍流还是弱湍流，m=2的涡旋光束在盐度为4.35‰的水下湍流中的闪烁因子都大于其在盐度为2.42‰的水下湍流中所对应的闪烁因子。另外，m=2的涡旋光束传输到相同的距离时，其闪烁因子随着水下湍流的盐度和强度的增大而增大。不同盐度条件下，m=2的涡旋光束的径向闪烁因子随径向距离的增大呈先减小后增大的变化趋势。另外，搭建了传输距离更长的实验装置，在20米的传输距离内，拓扑电荷m=2的涡旋光束的闪烁因子远高于高斯光束所对应的闪烁因子，且m=2的涡旋光束和高斯光束的闪烁因子都随着传输距离的增大而增大。Abstract: It is very important to study the propagation characteristics of light beams in ocean turbulence. In order to get closer to the actual situation, we build a device which can control both the salinity and the intensity of underwater turbulence to study the propagation characteristics of vortex beams and a Gaussian beam in underwater turbulence. The results show that compared with the underwater turbulence without sea salt, the light spot will be more diffuse and the light intensity will be weaker in the underwater turbulence with sea salt. When the topological charge m is 2, the scintillation index of the vortex beam in the underwater turbulence with salinity of 4.35‰ is larger than that in the underwater turbulence with salinity of 2.42‰, no matter it is strong turbulence or weak turbulence. When the vortex beam with m=2 propagates to the same distance, the scintillation index increases with the increment of the salinity and the intensity of underwater turbulence. Under different salinity conditions, the radial scintillation index of the vortex beam with m=2 decreases firstly and then increases with the increase of the radial distance. In addition, we set up another experimental device which can transmit a longer distance. The scintillation index of the vortex beam with m=2 is much higher than that of the Gaussian beam in the underwater turbulence within 20 m propagation distance, and the scintillation indices of both the vortex beam with m=2 and the Gaussian beam increase with the increase of the propagation distance.
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Key words:
- vortex beam /
- underwater turbulence /
- scintillation index /
- salinity /
- propagation
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Figure 1. Schematic diagram of vortex beams propagating in underwater turbulence. L1, L2, thin lenses; SPP, spiral phase plate; M1, M2, reflectors
Figure 2. The practical photos of the experimental device. (a) Weak turbulence; (b) strong turbulence
Figure 3. The scintillation of the vortex beam with m=2 transmitted to 3.6 meters in weak underwater turbulence with the SA =2.42 ‰
Figure 4. The intensity patterns of the vortex beam with m=2 propagating in both the weak and strong underwater turbulences with salinity of 0. (a) z=3.6 m, weak turbulence; (b) z=3.6 m, strong turbulence; (c) z=5.4 m, weak turbulence;(d) z=5.4 m, strong turbulence
Figure 5. The intensity patterns of the vortex beam with m=2 propagating in both the weak and strong underwater turbulences with the salinity of 2.42 ‰. (a) z=3.6 m, weak turbulence; (b) z=3.6 m, strong turbulence; (c) z=5.4 m, weak turbulence; (d) z=5.4 m, strong turbulence
Figure 6. Scintillation index of the vortex beam with m=2 varying with propagation distance in the water turbulence with different salinities in (a) weak turbulence and (b) strong turbulence
Figure 7. The effect of salinity on scintillation index of the vortex beam with m=2 at 3.6 m propagation distance in (a) weak turbulence and (b) strong turbulence
Figure 8. Scintillation index of the vortex beam with m=2 at 3.6 m propagation distance in (a) weak turbulence and (b) strong turbulence
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[1] GÖKÇE M C, BAYKAL Y. Scintillation analysis of multiple-input single-output underwater optical links[J]. Applied Optics, 2016, 55(22): 6130-6136. doi: 10.1364/AO.55.006130 [2] ISHIMARU A. Wave Propagation and Scattering in Random Media[M]. New York: Academic Press, 1978. [3] HOU W L. A simple underwater imaging model[J]. Optics Letters, 2009, 34(17): 2688-2690. doi: 10.1364/OL.34.002688 [4] LUO B, WU G H, YIN L F, et al. Propagation of optical coherence lattices in oceanic turbulence[J]. Optics Communications, 2018, 425: 80-84. doi: 10.1016/j.optcom.2018.04.076 [5] ATA Y, BAYKAL Y. Effect of anisotropy on bit error rate for an asymmetrical Gaussian beam in a turbulent ocean[J]. Applied Optics, 2018, 57(9): 2258-2262. doi: 10.1364/AO.57.002258 [6] JOHNSON L J, GREEN R J, LEESON M S. Underwater optical wireless communications: depth dependent variations in attenuation[J]. Applied Optics, 2013, 52(33): 7867-7873. doi: 10.1364/AO.52.007867 [7] CHENG M J, GUO L X, LI J T, et al. Channel capacity of the OAM-based free-space optical communication links with Bessel-Gauss beams in turbulent ocean[J]. IEEE Photonics Journal, 2016, 8(1): 7901411. [8] ZHAO SH M, WANG L, ZOU L, et al. Both channel coding and wavefront correction on the turbulence mitigation of optical communications using orbital angular momentum multiplexing[J]. Optics Communications, 2016, 376: 92-98. doi: 10.1016/j.optcom.2016.04.075 [9] WANG ZH Q, ZHANG P F, QIAO C H, et al. Scintillation index of Gaussian waves in weak turbulent ocean[J]. Optics Communications, 2016, 380: 79-86. doi: 10.1016/j.optcom.2016.05.089 [10] LU T F, ZHANG K N, WU Z J, et al. Propagation properties of elliptical vortex beams in turbulent ocean[J]. Chinese Optics, 2020, 13(2): 323-332. (in Chinese) doi: 10.3788/co.20201302.0323 [11] LI Y, ZHANG Y X, ZHU Y. Oceanic spectrum of unstable stratification turbulence with outer scale and scintillation index of Gaussian-beam wave[J]. Optics Express, 2019, 27(5): 7656-7672. doi: 10.1364/OE.27.007656 [12] EYYUBOĞLU H T. Apertured averaged scintillation of fully and partially coherent Gaussian, annular Gaussian, flat toped and dark hollow beams[J]. Optics Communications, 2015, 339: 141-147. doi: 10.1016/j.optcom.2014.11.070 [13] BAYKAL Y. Higher order mode laser beam scintillations in oceanic medium[J]. Waves in Random and Complex Media, 2016, 26(1): 21-29. doi: 10.1080/17455030.2015.1099760 [14] BAYKAL Y. Scintillation index in strong oceanic turbulence[J]. Optics Communications, 2016, 375: 15-18. doi: 10.1016/j.optcom.2016.05.002 [15] GERÇEKCIOĞLU H. Bit error rate of focused Gaussian beams in weak oceanic turbulence[J]. Journal of the Optical Society of America A, 2014, 31(9): 1963-1968. doi: 10.1364/JOSAA.31.001963 [16] ATA Y, BAYKAL Y. Scintillations of optical plane and spherical waves in underwater turbulence[J]. Journal of the Optical Society of America A, 2014, 31(7): 1552-1556. doi: 10.1364/JOSAA.31.001552 [17] YI X, LI Z, LIU Z J. Underwater optical communication performance for laser beam propagation through weak oceanic turbulence[J]. Applied Optics, 2015, 54(6): 1273-1278. doi: 10.1364/AO.54.001273 [18] YOUSEFI M, KASHANI F D, GOLMOHAMMADY S, et al. Scintillation and bit error rate analysis of a phase-locked partially coherent flat-topped array laser beam in oceanic turbulence[J]. Journal of the Optical Society of America A, 2017, 34(12): 2126-2137. doi: 10.1364/JOSAA.34.002126 [19] CUI Z M, YUE P, Yi X, et al. Scintillation of a partially coherent beam with pointing errors resulting from a slightly skewed underwater platform in oceanic turbulence[J]. Applied Optics, 2019, 58(16): 4443-4449. doi: 10.1364/AO.58.004443 [20] BRAMBILLA M, BATTIPEDE F, LUGIATO L A, et al. Transverse laser patterns. I. Phase singularity crystals[J]. Physical Review A, 1991, 43(9): 5090-5113. doi: 10.1103/PhysRevA.43.5090 [21] BEIJERSBERGEN M W, ALLEN L, VAN DER VEEN H E L O, et al. Astigmatic laser mode converters and transfer of orbital angular momentum[J]. Optics Communications, 1993, 96(1-3): 123-132. doi: 10.1016/0030-4018(93)90535-D [22] TAO S H, YUAN X C, LIN J, et al. Influence of geometric shape of optically trapped particles on the optical rotation induced by vortex beams[J]. Journal of Applied Physics, 2006, 100(4): 043105. doi: 10.1063/1.2260823 [23] FRIESE M E J, RUBINSZTEIN-DUNLOP H, GOLD J, et al. Optically driven micromachine elements[J]. Applied Physics Letters, 2001, 78(4): 547-549. doi: 10.1063/1.1339995 [24] GIBSON G, COURTIAL J, PADGETT M J, et al. Free-space information transfer using light beams carrying orbital angular momentum[J]. Optics Express, 2004, 12(22): 5448-5456. doi: 10.1364/OPEX.12.005448 [25] XU J, ZHAO D M. Propagation of a stochastic electromagnetic vortex beam in the oceanic turbulence[J]. Optics &Laser Technology, 2014, 57: 189-193. [26] LIU ZH L, CHEN J L, ZHAO D M. Experimental study of propagation properties of vortex beams in oceanic turbulence[J]. Applied Optics, 2017, 56(12): 3577-3582. doi: 10.1364/AO.56.003577 [27] LU T F, LIU Y X, PU J X. Experimental study on scintillation index of vortex beam propagation in underwater turbulence[J]. Acta Photonica Sinica, 2019, 48(12): 1214004. (in Chinese) doi: 10.3788/gzxb20194812.1214004 [28] EYYUBOĞLU H T. Estimation of aperture averaged scintillations in weak turbulence regime for annular, sinusoidal and hyperbolic Gaussian beams using random phase screen[J]. Optics &Laser Technology, 2013, 52: 96-102. -
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