Ber of Annular Beams in Weak Oceanic Turbulence

Abstract

Based on Rytov method, on-axis scintillation index of laser communication link in a weak oceanic medium is formulated for collimated annular beam. Employing these obtained scintillation values, average bit error rate (<BER>) is evaluated where the intensity has log-normal distribution.Scintillation indices of collimated annular beams are found for fixed primary source size w için bulunur. Paralelleştirilmiş halka hüzmesi için kayanak büyüklüğü ve ortalama sinyal gürültü oranı (<SNR>)' na göre <BER>, birim kütle akışkanı ve kaynak boyutları için türbülans kinetik enerjinin çeşitli dağılım oranı için sergilenmektedir. Belirtilen iletişim bağlantısında, halkasal hüzmelerin ikincil kaynak boyutu sıfıra eşit olduğunda, yani Gaussian hüzmesi olduğunda, <BER> daha fazla avantaj sağlayacaktır.

Depth dependence of oceanic turbulence optical power spectrum under any temperature and salinity concentration

“…where the necessary functions and the parameters involved in equation (18) are defined in equations (2)- (17). While all studies given in [12][13][14][15][16][17][18][19][20][21][22][23][24] are carried out assuming certain values for all oceanic turbulence parameters such as the rate of dissipation of turbulent kinetic energy per unit mass of fluid, Kolmogorov microscale, rate of the dissipation of mean-squared temperature, rate of dissipation of mean-squared salinity and rate of dissipation of mean-squared coupling, average temperature and average salinity. These parameters are expressed with realistic values in [25], including the Atlantic Ocean for high, mid and low latitude regions.…”

“…Moreover, on this subject, various model studies have been proposed to match the reality. With these models found out in this medium employed by taking salinity and temperature values as point values for power spectrum of underwater optical turbulence; the plane-and spherical-wave scintillation index are investigated in weak turbulence regime [12], the Prandtl/Schmidt numbers of the advected scalars are given for new model as parameters that may vary independently in the selected interval [13], the expressions are derived for the Prandtl/Schmidt numbers and the eddy diffusivity ratio [14], the on-axis scintillation index of a focused Gaussian and annular beams in weak oceanic turbulence is shown by using the Rytov method [15,16], BER performance of the PPM optical wireless communication (OWC) system is found at smaller data bit rates [17], the evolution of spectra of Gaussian Schell-model beams with initial Gaussian spectral profile is examined on propagation in turbulent ocean [18], a simplified spatial power spectrum model of turbulent fluctuations of the seawater refraction index as an explicit function of eddy diffusivity ratio and the performance of vertical underwater visible light communication links are obtained [19,20]. Field correlations of partially coherent optical beams at the receiver plane in underwater turbulence are studied [21], laser beam scintillations of LIDAR operating in weak oceanic turbulence are found for the first time [22] and enhanced backscatter in LIDAR systems with retro-reflectors operating through a turbulent ocean have been calculated [23].…”

Bit error rate of M-pulse position modulated laser beams for vertical links operating in weak oceanic turbulence

“…In oceanic medium, one of the first studies is the one including the scintillation indices of collimated Gaussian, of focused Gaussian, of plane and of spherical beams compared among themselves. Furthermore, performance of focused Gaussian beams [25] and of annular beams are examined in weak oceanic turbulence [26]. Moreover, the scintillations of spherical, of plane and of the Gaussian beam waves in weak and strong oceanic turbulence are reported [27][28][29][30].…”

“…Parameters, such as , which are used in the calculations and figures obtained in previous articles [6][7][8][9][10][11][12][13][14][15][16][26][27][28][29][30][31][32][33][34][35][36][37][38][39] with the support of Ref. [42], are not taken as constants.…”

Depth dependence of power spectrum in underwater turbulence

“…Underwater, being a very important medium, attracts many researchers around the world to examine various optical propagation applications such as wireless communication links, especially with the use of wireless optical communications [1][2][3][4], optical imaging systems [5] and laser radars [6]. Power spectra of underwater optical turbulence is first introduced and precise underwater turbulence hypothesis is provided by conveniently relating its temporal and spatial statistics by Taylor [7,8].…”