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Cuneyt Berkdemir

Publications and source records attributed to Cuneyt Berkdemir.

11 recordsLinked to original sources
arXiv2009

Modified l-states of diatomic molecules subject to central potentials plus an angle-dependent potential

We present modified $\ell$-states of diatomic molecules by solving the radial and angle-dependent parts of the Schrödinger equation for central potentials, such as Morse and Kratzer, plus an exactly solvable angle-dependent potential $V_θ(θ)/r^2$ within the framework of the Nikiforov-Uvarov (NU) method. We emphasize that the contribution which comes from the solution of the Schrödinger equation for the angle-dependent potential modifies the usual angular momentum quantum number $\ell$. We calculate explicitly bound state energies of a number of neutral diatomic molecules composed of a first-row transition metal and main-group elements for both Morse and Kratzer potentials plus an angle-dependent potential.

quant-ph↗
arXiv2006

Systematical Approach to the Exact Solution of the Dirac Equation for A Special Form of the Woods-Saxon Potential

Exact solution of the Dirac equation for a special form of the Woods-Saxon potential is obtained for the s-states. The energy eigenvalues and two-component spinor wave functions are derived by using a systematical method which is called as Nikiforov-Uvarov. It is seen that the energy eigenvalues strongly depend on the potential parameters. In addition, it is also shown that the non-relativistic limit can be reached easily and directly.

nucl-th↗
arXiv2005

The performance analysis dependent on the temperature for EDFAs pumped at 1480 nm: A more accurate propagation equation

An analytically expression for the temperature dependence of the signal gain of an erbium-doped fiber amplifier (EDFA) pumped at 1480 \textit{nm} are theoretically obtained by solving the propagation equations with the amplified spontaneous emission (ASE). It is seen that the temperature dependence of the gain strongly depends on the distribution of population of Er$^{3+}$-ions in the second level. In addition, the output pump power and the intrinsic saturation power of the signal beam are obtained as a function of the temperature. Numerical calculations are carried out for the temperature range from $-$ 20 to $+$ 60 \textit {$^{o}$C} and the various fiber lengths. But the other gain parameters, such as the pump and signal wavelengths and their powers, are taken as constants. It is shown that the gain decreases with increasing temperature within the range of $L\leq 27 m$.

physics.optics↗
arXiv2005

Rotational Correction on the Morse Potential Through the Pekeris Approximation and Nikiforov-Uvarov Method

The Nikiforov-Uvarov method is employed to calculate the the Schrodinger equation with a rotation Morse potential. The bound state energy eigenvalues and the corresponding eigenfunction are obtained. All of these calculation present an effective and clear method under a Pekeris approximation to solve a rotation Morse model. Meanwhile the results got here are in a good agreement with ones before.

quant-ph↗
arXiv2005

An investigation of the temperature dependency of the relative population inversion and the gain in EDFAs by the modified rate equations

The dependence of the relative population inversion in Er3+-doped fiber amplifiers (EDFAs) upon temperature and cross sections, taking into account the amplified spontaneous emission (ASE), are investigated theoretically by the modified rate equation model for 980 nm and 1470 nm pumping conditions. For the temperature range from 0 to +50 oC and at the different signal wavelengths, the temperature and cross section dependent gain characteristics with respect to pump powers are also examined in detail for the both conditions. As a consequence, the dependence of the performance of EDFAs on temperature for 980 nm pumping is weaker than that for 1470 nm pumping, not only at room temperature but also at the temperature range of 0 to +50 oC. However, the performance of EDFAs is more efficient at the pumping wavelength of 1470 nm than that of 980 nm for a wide range of temperature and high-pump powers. The results of this theoretical model are a good agreement with the experimental ones in the literature.

physics.optics↗
arXiv2004

A novel approach for the temperature dependency of saturated signal power in EDFAs

The temperature dependency of the saturated signal power for the transition in erbium-doped fiber amplifiers (EDFAs) pumped at 980 nm and 1480 nm pump wavelengths within a temperature range from 20 to 60 oC are investigated by a novel approach. For 1480 nm pumping regime, it is seen that the saturated signal power increases more quickly than that of 980 nm pumping regime, with the increasing temperature. The variation in the saturated signal power with temperature is nearly constant at 980 nm pumping regime. In addition, the population inversion with respect to the increasing normalized signal power is examined and it is seen that it is independent of temperature for 980 nm but it strongly depends on temperature for 1480 nm especially at lower normalized signal powers.

physics.optics↗
arXiv2004

Exact Solutions of the Duffin Kemmer Petiau Equation for the Deformed Hulthen Potential

Using the Nikiforov Uvarov method, an application of the relativistic Duffin Kemmer Petiau equation in the presence of a deformed Hulthen potential is presented for spin zero particles. We derived the first order coupled differential radial equations which enable the energy eigenvalues as well as the full wavefunctions to be evaluated by using of the Nikiforov Uvarov method that can be written in terms of the hypergeometric polynomials.

quant-ph↗