Elektrik Elektronik Mühendisliği Bölümü Yayın Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/411
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Article Citation - WoS: 7Citation - Scopus: 7Intensity Fluctuations in Biological Tissues at Any Turbulence Strength(Iop Publishing Ltd, 2022) Baykal, Yahya; Ata, Yalcin; Gokce, Muhsin CanerThis study investigates the intensity fluctuations of the optical plane and spherical waves in biological tissue that experience any strength of turbulence. Biological tissue is a random and complex medium for optical wave propagation, having a power spectrum reflecting the turbulent characteristics that depend on the structural parameters. It is important to accurately determine the strength of turbulence and classify turbulence regimes for the correct modeling of the behavior of the optical wave propagation. To classify weak, moderate and strong turbulent regimes, closed-form expressions of modified Rytov variances are obtained. Based on the modified Rytov variance that involves the large-scale and small-scale variations, the intensity fluctuations specified by the metric of scintillation index, are calculated versus various parameters such as the propagation distance, refractive index, characteristic length of heterogeneity, small length-scale factor, wavelength, fractal dimension and strength of the refractive index fluctuations. Behavior of optical plane and spherical waves in different turbulent regimes and the comparison of intensity fluctuations in different specimens of human and animal tissues are shown.Editorial Citation - WoS: 1Citation - Scopus: 1Editorial: Optical Wave Propagation and Communication in Turbulent Media(Frontiers Media Sa, 2023) Baykal, YahyaArticle Citation - WoS: 6Citation - Scopus: 5Anisotropic Non-Kolmogorov Turbulence Effect on Transmittance of Multi-Gaussian Beam(Taylor & Francis Ltd, 2020) Ata, Yalcin; Baykal, YahyaThe effect of anisotropic non-Kolmogorov turbulent atmosphere on multi-Gaussian beam is investigated and the results are presented against different beam and medium parameters. Results show that anisotropy increases the power efficiency of wireless communication systems. Besides anisotropy, turbulence effects on the multi-Gaussian optical beam are represented versus the beam source size, beam flatness order, propagation distance, inner scale length, turbulence strength, non-Kolmogorov turbulence power law exponent, wavelength, inner and outer source sizes for flat-topped and annular beams.Article Citation - WoS: 4Citation - Scopus: 4The Analysis of Anisotropic the Non-Kolmogorov Turbulence Effect on Asymmetrical Gaussian Beam Propagation in a Marine Atmosphere(Iop Publishing Ltd, 2019) Ata, Yalcin; Baykal, YahyaThe variations of the scintillation index of an asymmetrical Gaussian beam are investigated when the beam propagates in anisotropic non-Kolmogorov marine atmospheric turbulence. The results indicate that the scintillation decreases when the anisotropy factors in both x and y directions increase. Increases in the beam asymmetry ratio and the inner scale length increase the scintillation index level. The scintillations are found to increase as the propagation distance and structure constant increase, and as the wavelength decreases. Being valid for any asymmetry and anisotropic factor, for small values of the power law exponent, alpha of non-Kolmogorov marine atmospheric turbulence, the scintillation index tends to increase proportionally with alpha. However, as alpha is further increased, the scintillation index starts to decrease after reaching a peak value. Larger anisotropy in the non-Kolmogorov marine turbulence is found to be preferable since the scintillation index is found to decrease at large anisotropic factors.Article Citation - WoS: 17Citation - Scopus: 16Transmittance of Multi Gaussian Optical Beams for Uplink Applications in Atmospheric Turbulence(Ieee-inst Electrical Electronics Engineers inc, 2015) Ata, Yalcin; Baykal, YahyaOn-axis slant path uplink transmittance (used in short as transmittance throughout the text) for multi Gaussian optical beam in Kolmogorov atmospheric turbulent medium is investigated. It is observed that for both the flat-topped and the annular beams, as the propagation distance, wind speed and the zenith angle increase, the transmittance decreases. The transmittance of flat-topped beams increases when the number of beams, source size or the wavelength increases. For the annular beam, when the outer/inner beam size ratio is kept constant, larger source sizes yield larger transmittance values. Transmittance of the thicker annular beams is found to be larger than the transmittance of the thinner annular beams.