Experimental study of the effects of thermally induced optical turbulence on underwater wireless optical communication link parameters. (3rd January 2020)

• Record Type: Journal Article
• Authors: Yousefi, Masoud; Dabbagh Kashani, Fatemeh; Aghajani, Amir; Hedayati Rad, Mohammad Reza
• Is Part Of: Journal of optics. Volume 22:Number 2(2020)
• Publication Date: 2020-01-03
• Subjects: BER -- laser beam propagation through turbulence -- probability density function -- SNR -- underwater optical communication link -- aperture averaged scintillation; Optics -- Periodicals; 535.05
• DOI: 10.1088/2040-8986/ab61c8
• Languages: English
• ISSNs: 2040-8978

Abstract

Abstract: In this experimental research, the effects of refractive index fluctuations resulting from temperature fluctuations on some of the most important underwater communication link parameters such as the average received power, signal to noise ratio (SNR) and normalized power variance (aperture averaged scintillation) has been experimentally investigated. Moreover, by introducing a new probability density function which is fitted more appropriately to the experimental data obtained from our simulator tank, the bit error rate (BER) behavior of an underwater wireless optical communication (UWOC) link is also studied. These investigations are essential due to the optical turbulence limiting effects on the performance of UWOC systems. The experimental results indicate that reduction of the aperture averaged scintillation effects by using of optical components in the transmitter and receiver of UWOC links can enhance their performance. In general, increasing the strength of the optical turbulence (by increasing the temperature gradient induced by the rod heater) or the distance of the localized turbulence screen generated by temperature gradient from the transmitter plane, the aperture averaged scintillation decreases and consequently the SNR raises whilst the BER declines. Also, expanding the aperture diameter of the receiver optics reduces the normalized power variance which leads to decrease and increase in the BER and the SNR amounts, respectively. The results are presented as experimental simulation graphs.