Experimental and Theoretical Investigation of the Effect of Salinity on Attenuation of 405 nm and 520 nm Laser Beams in Underwater wireless optical communication systems
DOI:
https://doi.org/10.24237/04.04.774Keywords:
UWOC, SNR, Laser diode, Attenuation. Scaring and absorptionAbstract
In this paper, the effect of salinity on laser signals was theoretically and experimentally examined. Here a comparative analysis of the two wavelengths in different saline water environments was conducted. Both the theoretical and experimental analyses were performed based on an underwater optical communication (UWOC) system. Based on the UWOC, 405 nm and 520 nm laser wavelengths were employed with an optical power of 10 mW and results under water [channel of varying salinity levels (10–80 g/L) were investigated. The values of absorption and scattering coefficients for the sea environment were theoretically estimated in the visible wavelength region. The theoretical results showed that the 400–550 nm interval represents an optical transmission window for laser light, resulting in lower absorption coefficients. However, in high-salinity marine environments (high-concentration), the transmission windows across the visible region showed almost negligible effects due to increased scattering and absorption. This indicates that the scattering process in specific water types slightly decreases with increasing wavelength. This investigation is important to assess the suitability of (405and520) nm lasers as potential choices for efficient UWOC systems, particularly in dense or saline waters. It was found that power loss at maximum link distance increases with salinity level due to the effect of attenuation. As salinity level rises, the practical signal-to-noise ratio (SNR) decreases due to higher transmission losses caused by attenuation. Furthermore, the refractive index as a function of temperatures was theoretically estimated for 405 nm and 520 nm laser diodes. The results show that increasing the temperatures led to decrees in the estimated refractive index.
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References
[1]
D. Brdar, N. Lopac, A. Lesch, and I. Jurdana, "Design of a conceptual underwater wireless communication system integrating electromagnetic and optical technologies", Sci. J. Maritime Res. – Pomorstvo, pp. 141–149(2025), DOI: https://doi.org/10.31217/p.39.1.11
[2]
Y. Kida, M. Deguchi, and T. Shimura, "Experimental result for a high-rate underwater acoustic communication in deep sea for a manned submersible shinkai6500", J. Mar. Acoust. Soc. Jpn., vol. 45, pp. 197–203(2018), DOI: https://doi.org/10.3135/jmasj.45.197
[3]
C. Fang, S. Li, Y. Wang, and K. Wang, "High-speed underwater optical wireless communication with advanced signal processing methods survey", Photonics, vol. 10, no. 7, p. 811, July (2023), DOI: https://doi.org/10.3390/photonics10070811
[4]
1st-Relief GmbH, "ScubaNav and ScubaPOIs - projects funded by the FFG (www.ffg.at) Project Reports", Graz, Austria, 2022–2024.
[5]
D. Palaić, N. Lopac, I. Jurdana, and D. Brdar, "Advancements and Challenges in Underwater Wireless Optical Communication in the Marine Environment", in Proc. 47th MIPRO ICT and Electronics Convention (MIPRO), Opatija, Croatia, pp. 1760–1765(2024), DOI: https://doi.org/10.1109/MIPRO60963.2024.10569767
[6]
S. Ishibashi and K.-I. Susuki, "1Gbps x 100m Underwater Optical Wireless Communication Using Laser Module in Deep Sea", in Proc. OCEANS 2022, Hampton Roads, VA, USA, 2022, pp. 1–7(2022), DOI: https://doi.org/10.1109/OCEANS47191.2022.9976975
[7]
Y. Weng, T. Matsuda, Y. Sekimori, J. Pajarinen, J. Peters, and T. Maki, "Pointing Error Control of Underwater Wireless Optical Communication on Mobile Platform", IEEE Photonics Technology Letters, vol. 34, no. 13, pp. 699–702, July (2022), DOI: https://doi.org/10.1109/LPT.2022.3181336
[8]
S. A. Adnan, H. A. Hassan, A. Alchalaby, and A. C. Kadhim, "Experimental study of underwater wireless optical communication from clean water to turbid harbor under various conditions", Int. J. Design & Nature and Ecodynamics, vol. 16, no. 2, pp. 219–226(2021), DOI: https://doi.org/10.18280/ijdne.160212
[9]
X. Ke, and G. Li, "Characterization of Blue-Green Light Non-Line-of-Sight Transmission in Seawater", Optics and Photonics Journal, vol. 12, pp. 234–252(2022), DOI: https://doi.org/10.4236/opj.2022.1211018
[10]
S. J. Zhu, X. W. Chen, X. Y. Liu, G. Q. Zhang, and P. F. Tian, "Recent Progress in and Perspectives of Underwater Wireless Optical Communication", Progress in Quantum Electronics, vol. 73, Article ID 100274, (2020), DOI: https://doi.org/10.1016/j.pquantelec.2020.100274
[11]
L. B. Hu, X. D. Zhang, and M. J. Perry, "Light Scattering by Pure Seawater at Subzero Temperatures", Deep-Sea Research Part I, vol. 162, Article ID 103306, (2020), DOI: https://doi.org/10.1016/j.dsr.2020.103306
[12]
Z. Q. Zeng, S. Fu, H. H. Zhang, Y. H. Dong, and J. L. Cheng, "A Survey of Underwater Optical Wireless Communications", IEEE Communications Surveys & Tutorials, vol. 19, pp. 204–238(2017), DOI: https://doi.org/10.1109/COMST.2016.2618841
[13]
C. Chen, "100 Gbps Indoor Access and 4.8 Gbps Outdoor Point-to-Point LiFi Transmission Systems Using Laser-Based Light Sources", J. Lightwave Technol., vol. 42, no. 12, pp. 4146–4157, June (2024), DOI: https://doi.org/10.1109/JLT.2024.3400192
[14]
H. Chen, "Toward Long-Distance Underwater Wireless Optical Communication Based on A High-Sensitivity Single Photon Avalanche Diode", IEEE Photonics Journal, vol. 12, no. 3, Art. no. 7902510, June (2020), DOI: https://doi.org/10.1109/JPHOT.2020.2985205
[15]
O. A. Ojediran, A. A. Ponnle, and S. A. Oyetunji, "Experimental Study on Transmission of Visible Light in Table Salt Water and Effect on Underwater Wireless Optical Communication", Eur. J. Electr. Eng. Comput. Sci., vol. 6, no. 2, pp. 25–32, Mar. (2022), DOI: https://doi.org/10.38032/jea.2023.03.004
[16]
X. Han, Y. Peng, Y. Zhang, Z. Ma, and J. Wang, "Research on the attenuation characteristics of some inorganic salts in seawater", J. Eur. Opt. Soc. Rapid Publ., vol. 10, p. 15045, (2015), DOI: https://doi.org/10.2971/jeos.2015.15045
[17]
M. Ali, D. N. K. Jayakody, Y. A. Chursin, "Recent Advances and Future Directions on Underwater Wireless Communications", Arch. Comput. Methods Eng., vol. 27, pp. 1379–1412, (2020), DOI: https://doi.org/10.1007/s11831-019-09354-8
[18]
D. Akkaynak, T. Treibitz, T. Shlesinger, Y. Loya, R. Tamir, and D. Iluz, "What is the space of attenuation coefficients in underwater computer vision?", in Proc. IEEE Conf. Comput. Vis. Pattern Recognit., pp. 4931–4940(2017), DOI: https://doi.org/10.1109/CVPR.2017.68
[19]
S. Arnon, "Underwater optical wireless communication network", Opt. Eng., vol. 49, 015003, (2010), DOI: https://doi.org/10.1117/1.3280288
[20]
C. D. Mobley, “Light and Water: Radiative Transfer in Natural Waters”, Academic Press, San Diego, CA, 1994.
[21]
G. Schirripa Spagnolo, L. Cozzella, and F. Leccese, "Underwater Optical Wireless Communications: Overview", Sensors, vol. 20, no. 8, 2261, (2020), DOI: https://doi.org/10.3390/s20082261
[22]
J. Xu, Y. Song, X. Yu, A. Lin, M. Kong, J. Han, and N. Deng, "Underwater wireless transmission of high-speed QAM-OFDM signals using a compact red-light laser", Opt. Express, vol. 24, pp. 8097–8109(2016), DOI: https://doi.org/10.1364/oe.24.008097
[23]
A. N. Bashkatov and E. A. Genina, "Water refractive index in dependence on temperature and wavelength: A simple approximation", Proc. SPIE, vol. 5068, pp. 393–395(2003), DOI: https://doi.org/10.1117/12.518857
[24]
L. D. R. Lide (Ed.), Index of Refraction of Water, Handbook of Chemistry and Physics, CRC Press, Boca Raton, FL, 2000–2001.
[25]
S. Al-Zhrani, N. M. Bedaiwi, I. F. El-Ramli, A. Z. Barasheed, A. Abduldaiem, Y. Al-Hadeethi, and A. Umar, "Underwater optical communications: A brief overview and recent developments", Eng. Sci., vol. 16, pp. 146–186(2021), DOI: http://dx.doi.org/10.30919/es8d574
[26]
J. Wang, C. Lu, S. Li, and Z. Xu, "100 m/500 Mbps underwater optical wireless communication using an NRZ-OOK modulated 520 nm laser diode", Opt. Express, vol. 27, no. 9, pp. 12171–12181(2019), DOI: https://doi.org/10.1364/OE.27.012171
[27]
A. A. Ponnle, O. A. Ojediran, and S. A. Oyetunji, "An Alternative Experimental Method for Determination of Light Beam Attenuation Coefficient in Underwater Wireless Optical Communication", EJECE, vol. 6, no. 3, (2022), DOI: https://doi.org/10.24018/ejece.2022.6.3.439
[28]
B. Woodward and H. Sari, "Underwater speech communications with a modulated laser," Appl. Phys. B, vol. 91, pp. 189–194, 2008.
[29]
A. Sangeetha, M. P. Abraham, and N. Bruno, "Analysis of underwater environment and establishment of underwater wireless optical communication link", Eur. J. Sci. Res., vol. 87, no. 3, pp. 349–358(2012)
[30]
M. N. Uddin, M. M. Rahman, and M. S. Ali, "Performance Analysis of Different Loss Mechanisms in Optical Fiber Communication", Comput. Appl.: Int. J., vol. 2, no. 2, (2015), DOI: https://doi.org/10.5121/CAIJ.2015.2201
[31]
M. AL-Deen, M. Ali, and Z. Saleh, "Improving the optical link for UVLC using MIMO technique", J. Opt. Commun., vol. 44, suppl. 1, pp. s1671–s1680(2023), DOI: https://doi.org/10.1515/joc-2021-0050
[32]
A. Keskin, F. Genç, S. A. Arpali, Ö. K. Catmakas, Y. Baykal, and Ç. Arpali, "Effects of focused and collimated laser beams on the performance of underwater wireless optical communication links", in Proc. 4th Int. Workshop on Optical Wireless Communications, pp. 41–45(2015), DOI: https://doi.org/10.1109/IWOW.2015.7342262
[33]
A. Shofuro, A. Wijayanto, Y. G. Liu, S. Liaw, P. Lee, C. Yeh, and O. Hiroshi, "Study on Temperature and Water Turbulence Impact on Saline Water-Based Wireless Optical Communication", Photonics, vol. 10, no. 4, p. 383, pp. 2–10(2023), DOI: https://doi.org/10.3390/photonics10040383
[34]
H. R. Gordon, O. B. Brown, and M. M. Jacobs, "Computed Relationships Between the Inherent and Apparent Optical Properties of a Flat Homogeneous Ocean", Appl. Opt., vol. 14, pp. 417–427(1975), DOI: https://doi.org/10.1364/AO.14.000417
[35]
L. Prieur and S. Sathyendranath, "An Optical Classification of Coastal and Oceanic Waters Based on the Specific Spectral Absorption Curves of Phytoplankton Pigments, Dissolved Organic Matter, and Other Particulate Materials", Limnol. Oceanogr., vol. 26, no. 4, pp. 671–689(1981), DOI: https://doi.org/10.4319/lo.1981.26.4.0671
[36]
S. Kumar, S. Prince, J. V. Aravind, and S. Kumar, "Analysis on the effect of salinity in underwater wireless optical communication", Mar. Georesources Geotechnol., vol. 38, no. 3, pp. 291–301(2019), DOI: https://doi.org/10.1080/1064119X.2019.1569739
[37]
Y. Z. Yacobi, J. Köhler, F. Leunert, and A. Gitelson, "Phycocyanin-specific absorption coefficient: Eliminating the effect of chlorophylls absorption," Limnol. Oceanogr. Methods, vol. 13, no. 4, pp. 157–168(2015), DOI: https://doi.org/10.1002/lom3.10015
[38]
H. Hodara and R. J. Marquedant, "The signal/noise ratio concept in underwater optics", Appl. Opt., vol. 7, no. 3, pp. 527–534(1968), DOI: https://doi.org/10.1364/AO.7.000527
[39]
S. Afifah, J. K. Wei, L. Marlina, S. K. Liaw, P. J. Lee, and C. H. Yeh, "Performance evaluation of multi-wavelength visible light underwater optical communication", Opt. Lasers Eng., vol. 192, 109026, (2025), DOI: https://doi.org/10.1016/j.optlaseng.2025.109026
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