WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8653
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Article Citation - WoS: 183Citation - Scopus: 193Analysis of Reciprocity of Cos-Gaussian and Cosh-Gaussian Laser Beams in a Turbulent Atmosphere(Optical Soc Amer, 2004) Eyyuboglu, HT; Baykal, YIn a turbulent atmosphere, starting with a cos-Gaussian excitation at the source plane, the average intensity profile at the receiver plane is formulated. This average intensity profile is evaluated against the variations of link lengths, turbulence levels, two frequently used free-space optics wavelengths, and beam displacement parameters. We show that a cos-Gaussian beam, following a natural diffraction, is eventually transformed into a cosh-Gaussian beam. Combining our earlier results with the current findings, we conclude that cos-Gaussian and cosh-Gaussian beams act in a reciprocal manner after propagation in turbulence. The rates (paces) of conversion in the two directions are not the same. Although the conversion of cos-Gaussian beams to cosh-Gaussian beams can happen over a wide range of turbulence levels (low to moderate to high), the conversion of cosh-Gaussian beams to cos-Gaussian beams is pronounced under relatively stronger turbulence conditions. Source and propagation parameters that affect this reciprocity have been analyzed. (C) 2004 Optical Society of America.Article Citation - WoS: 37Citation - Scopus: 38Diffraction by a Black Half Plane: Modified Theory of Physical Optics Approach(Optical Soc Amer, 2005) Umul, YZThe scattered fields from a black half plane which absorbs all the incoming electromagnetic energy are evaluated by defining a new modified theory of physical optics surface current. This current eliminates the reflected fields, coming from the first stationary point of the reflection integral and only creates a reflected diffracted field. The incident scattered fields are found from the same integral, written for the perfectly conducting half plane. The scattered fields are evaluated by using the stationary phase method and edge point technique. The evaluated fields are plotted numerically. (c) 2005 Optical Society of America.Article Citation - WoS: 67Citation - Scopus: 67Equivalent Functions for the Fresnel Integral(Optical Soc Amer, 2005) Umul, YZFresnel integral is modeled with three equivalent functions. The first function is derived by considering the sum of the first term of the Fresnel integral's asymptotic expansion {(F) over cap (x)} and an exponential function which approaches to infinity at the zero of the Fresnel function's argument and has the properties of a unit step function. The second one is the sum of a unit step function and the transition function defined for the simplified uniform theory of diffraction. The third function considers directly eliminating the infinity coming from (F) over cap (x). The amplitude and the phase of Fresnel integral and its equivalent functions are compared numerically. The result is applied to the modified theory of physical optics solution of the diffraction of edge waves from a half plane problem. (c) 2005 Optical Society of America.Article Citation - WoS: 5Citation - Scopus: 5Raman Mode Non-Classicality Through Entangled Photon Coupling To Plasmonic Modes(Optical Soc Amer, 2018) Salmanogli, AhmadIn this article, non-classical properties of Raman modes are investigated. The original goal, actually, is to identify how and by which method we can induce non-classicality in Raman modes. We introduce a plasmonic system in which Raman dye molecules are buried between two shells of the plasmonic materials, similar to an onionlike core/shell nanoparticle. This system is excited by the entangled two-photon wave, followed by analysis of its dynamics of motion using the Heisenberg-Langevin equations by which the time evolution of the signalidler mode and Raman modes are derived. Interestingly, the entangled two-photon wave is coupled to the plasmonic modes, which are used to improve the non-classicality. It is shown that the exciting system with the entangled photons leads to inducing the non-classicality in Raman modes and entanglement between them. Moreover, it is seen that the plasmon-plasmon interaction in the gap region has a strong effect on the non-classicality of the input modes and also affects entangling of the Raman modes, which means that plasmonic modes generated by the core/shell nanoparticles manipulate the Raman modes' quantum properties. It is shown that the quantum properties in the designed system are dramatically influenced by the environmental temperature and the location of the Raman molecules in the gap region. The modeling results demonstrate that by changing the location of the Raman molecules, the non-classicality of the Raman modes and their entanglement are altered. Finally, as an important result, it is revealed that the Raman modes, such as the Stokes and anti-Stokes modes, show a revival behavior, which is a quantum phenomenon. (c) 2018 Optical Society of America.Article Citation - WoS: 112Citation - Scopus: 127Wave Structure Function and Spatial Coherence Radius of Plane and Spherical Waves Propagating Through Oceanic Turbulence(Optical Soc Amer, 2014) Lu, Lu; Ji, Xiaoling; Baykal, YahyaThe analytical formulae for the wave structure functions (WSF) and the spatial coherence radius of plane and spherical waves propagating through oceanic turbulence are derived. It is found that the Kolmogorov five-thirds power law of WSF is also valid for oceanic turbulence in the inertial range. The changes of the WSF and the spatial coherence radius versus different parameters of oceanic turbulence are examined. (C) 2014 Optical Society of America.Article Citation - WoS: 80Citation - Scopus: 85Propagation of an Airy Beam Through the Atmosphere(Optical Soc Amer, 2013) Ji, Xiaoling; Eyyuboglu, Halil T.; Ji, Guangming; Jia, XinhongIn this paper, the effect of thermal blooming of an Airy beam propagating through the atmosphere is examined, and the effect of atmospheric turbulence is not considered. The changes of the intensity distribution, the centroid position and the mean-squared beam width of an Airy beam propagating through the atmosphere are studied by using the four-dimensional (4D) computer code of the time-dependent propagation of Airy beams through the atmosphere. It is shown that an Airy beam can't retain its shape and the structure when the Airy beam propagates through the atmosphere due to thermal blooming except for the short propagation distance, or the short time, or the low beam power. The thermal blooming results in a central dip of the center lobe, and causes the center lobe to spread and decrease. In contrast with the center lobe, the side lobes are less affected by thermal blooming, such that the intensity maximum of the side lobe may be larger than that of the center lobe. However, the cross wind can reduce the effect of thermal blooming. When there exists the cross wind velocity v(x) in x direction, the dependence of centroid position in x direction on v(x) is not monotonic, and there exists a minimum, but the centroid position in y direction is nearly independent of v(x). (C) 2013 Optical Society of AmericaArticle Citation - WoS: 67Influence of Turbulence on the Effective Radius of Curvature of Radial Gaussian Array Beams(Optical Soc Amer, 2010) Ji, Xiaoling; Eyyuboglu, Halil T.; Baykal, YahyaThe analytical formula for the effective radius of curvature of radial Gaussian array beams propagating through atmospheric turbulence is derived, where coherent and incoherent beam combinations are considered. The influence of turbulence on the effective radius of curvature of radial Gaussian array beams is studied by using numerical calculation examples. (C) 2010 Optical Society of AmericaArticle Citation - WoS: 136Citation - Scopus: 148M<sup>2</Sup>-factor of Coherent and Partially Coherent Dark Hollow Beams Propagating in Turbulent Atmosphere(Optical Soc Amer, 2009) Yuan, Yangsheng; Cai, Yangjian; Qu, Jun; Eyyuboglu, Halil T.; Bayka, Yahya; Korotkova, Olga; Baykal, YahyaAnalytical formula is derived for the M-2-factor of coherent and partially coherent dark hollow beams (DHB) in turbulent atmosphere based on the extended Huygens-Fresnel integral and the second-order moments of the Wigner distribution function. Our numerical results show that the M-2-factor of a DHB in turbulent atmosphere increases on propagation, which is much different from its invariant properties in free-space, and is mainly determined by the parameters of the beam and the atmosphere. The relative M-2-factor of a DHB increases slower than that of Gaussian and flat-topped beams on propagation, which means a DHB is less affected by the atmospheric turbulence than Gaussian and flat-topped beams. Furthermore, the relative M-2-factor of a DHB with lower coherence, longer wavelength and larger dark size is less affected by the atmospheric turbulence. Our results will be useful in long-distance free-space optical communications. (C) 2009 Optical Society of AmericaArticle Citation - WoS: 53Citation - Scopus: 58Average Intensity and Spreading of an Elegant Hermite-Gaussian Beam in Turbulent Atmosphere(Optical Soc Amer, 2009) Yuan, Yangsheng; Cai, Yangjian; Qu, Jun; Eyyuboglu, Halil T.; Baykal, YahyaThe propagation of an elegant Hermite-Gaussian beam (EHGB) in turbulent atmosphere is investigated. Analytical propagation formulae for the average intensity and effective beam size of an EHGB in turbulent atmosphere are derived based on the extended Huygens-Fresnel integral. The corresponding results of a standard Hermite-Gaussian beam (SHGB) in turbulent atmosphere are also derived for the convenience of comparison. The intensity and spreading properties of EHGBs and SHGBs in turbulent atmosphere are studied numerically and comparatively. It is found that the propagation properties of EHGBs and SHGBs are much different from their properties in free space, and the EHGB and SHGB with higher orders are less affected by the turbulence. What's more, the SHGB spreads more rapidly than the EHGB in turbulent atmosphere under the same conditions. Our results will be useful in long-distance free-space optical communications. (C) 2009 Optical Society of AmericaArticle Citation - WoS: 113Citation - Scopus: 123Radiation Force of Coherent and Partially Coherent Flat-Topped Beams on a Rayleigh Particle(Optical Soc Amer, 2009) Zhao, Chengliang; Cai, Yangjian; Lu, Xuanhui; Eyyuboglu, Halil T.Propagations of coherent and partially coherent flat-topped beams through a focusing optical system are formulated. The radiation force on a Rayleigh dielectric sphere induced by focused coherent and partially coherent flat-topped beams is investigated theoretically. It is found that we can increase the transverse trapping range at the planes near the focal plane by increasing the flatness (i.e., beam order) of the flat-topped beam, and increase the transverse and longitudinal trapping ranges at the focal plane by decreasing the initial coherence of the flat-topped beam. Moreover the trapping stiffness of flat-topped beam becomes lower as the beam order increases or the initial coherence decreases. The trapping stability is also analyzed. (C) 2009 Optical Society of America