Data transmission in optical systems and increased transmission distance capacity benefit by using optical amplification wavelength division multiplexing (WDM) technology. The combination of four waves (FWM) is a non-linear effect in the wavelength division multiplex (WDM), when more than two wavelengths of light in a fiber launch will occur. FWM amount depends on the channel, the channel spacing and dispersion fiber, but is independent of the bit rate. A simple equation for the spectral line width is shown. Dispersion causes distortion of the transmitted signals and needs to be compensated to achieve a long-haul system. The four-wave mixing effect have been studied as one of the factors influencing by using OPTISYSTEM Software. In this paper, a new approach for suppressing the four-wave mixing (FWM) crosstalk by using the pairing combinations of differently linear-polarized optical signals is investigated. The simulation is conducted using an eight-channel system. The proposed technique is to suppress the FWM interaction using different input powers. It has been evaluated for single-mode fiber (SMF). FWM can be strongly reduced, when the polarization technique is conducted for SMF. We also compare our new method with a conventional method to demonstrate the effect of FWM as well. The comparison was conducted at an input power range of 2 dBm. Decreasing the input power can decrease the FWM effects. In the absence of the polarization technique the FWM power was –64 dBm at an input power of 2 dBm. The FWM power decreased to less than -82 dBm at a 2 dBm input power. The system performance greatly has been improved.

The main problemswith the use of fossil fuels is the restrictions on their access and the detrimental consequences of their use which causes a threat to human health and quality of life. Consequently, the use of other energy sources has become necessary. Renewable Energy as a permanent and clean energy source is an answer to this problem. One such energy source includes photovoltaic solar energy that is widely available as a reliable energy source. Research and Development of Photovoltaic Energy in general, will reduce costs and improve efficiency in both areas. CIGS solar cells have higher efficiency in comparison with other cells. Ion implantation and doping technique offers the unique structure of a solar cells. This paper will examine the performance of solar cells with Cu In1-x Gax Se2 structure. This willbe performed by Silvaco software. Effect of doping phosphorus (p) and Natrium (Na), as well as the value of x and thethickness of the various layers of the solar cell, on the efficiency of the cell, have been studied.

In this paper, scattering of a plane and monochromatic electromagnetic wave from a nano-wire is simulated using surface integral equations. First, integral equationsgoverning unknown fields on the surface is obtained based on Stratton-Cho surface integral equations. Then, the interaction of the wave with a non-plasmonic as well as a palsmonic nano-wire is considered. It is shown that in scattering of the wave from the non-plasmonic nano-wire the simple phenomena of refraction and transmission occur. On the other hand, the interaction of TM polarized light with plasmonic nano-wire excites surface plasmon waves. Simulations show that no surface plasmon is excited in interaction of TE polarized light with plasmonioc nano-wire. It is observed that, while increasing the frequency of incident light, the regime of scattering goes from electrostatic limit to simple geometric limit through diffraction region. In continuation, charge distribution induced by surface plasmon is simulated for different times. The simulation shows that a wave-like surface charge is excited and propagates on the surface.There is a very weak charge distribution within the nano-wire indicating that no light penetrates the wire.

In this paper the effects of transmittance, dispersion angle and diffusion length on the quantum efficiency of solar cells (QESC) have been simulated and investigated. Optical path technic is used for simulation. The results show that base thickness, diffusion length, dispersion angle, number of optical confinement path and transmission angles have an extremely effects on the QESC. Simulation results show that for optical paths with and QE can be achieved to 72% which is approximately 12% more than . The simulation results with grating in SC and reflecting about 100% at the end of the device show that QE increase to %47 with which is more than the results of device without grating. So the results show that the QESC increase with increasing the dispersion angle and diffusion length in the grating device.

Data transmission in optical systems and increased transmission distance capacity benefit by using optical amplification wavelength division multiplexing (WDM) technology. The combination of four waves (FWM) is a non-linear effect in the wavelength division multiplex (WDM), when more than two wavelengths of light in a fiber launch will occur. FWM amount depends on the channel, the channel spacing and dispersion fiber, but is independent of the bit rate. A simple equation for the spectral line width is shown. Dispersion causes distortion of the transmitted signals and needs to be compensated to achieve a long-haul system. The four-wave mixing effect have been studied as one of the factors influencing by using OPTISYSTEM Software. In this paper, a new approach for suppressing the four-wave mixing (FWM) crosstalk by using the pairing combinations of differently linear-polarized optical signals is investigated. The simulation is conducted using an eight-channel system. The proposed technique is to suppress the FWM interaction using different input powers. It has been evaluated for single-mode fiber (SMF). FWM can be strongly reduced, when the polarization technique is conducted for SMF. We also compare our new method with a conventional method to demonstrate the effect of FWM as well. The comparison was conducted at an input power range of 2 dBm. Decreasing the input power can decrease the FWM effects. In the absence of the polarization technique the FWM power was –64 dBm at an input power of 2 dBm. The FWM power decreased to less than -82 dBm at a 2 dBm input power. The system performance greatly has been improved.

In this paper, a photonic crystal waveguide with point defects and lattice constant perturbations of +5%, -5% are being investigated. Firstly waveguide structures with constant and specific parameters are being studied and photonic band gap diagrams for TE/TM modes are depicted; then pulse propagation in the frequencies available in the band gap are shown. After that, effects of parameters like refractive indicesand radius of the rods on the band gap diagram of TE/TMmodes are evaluated. It has beenshown that, by increasing the refractive indices and radius of the rods, band gap diagrams would be shifted to lower frequency amounts.

In this paper, the temperature dependence on optical absorption cross section of the core shell bimetallic nanoparticles (NPs) is investigated in quasi static approximation. Temperature dependence of the plasmon resonance is important issue because of recent applications of NPs of noble metal for heat treating of cancer and the computer chips. The effect of temperature on surface plasmon resonance and spectral properties of spherical core-shell NPs are studied by using the Drude Lorentz model. As temperatures increases, the spectrum can be expanded, and thus it causes to expand plasmon resonance absorption and a weak red shift in core-shell NPs. In addition, the temperature dependent absorption cross section of the material depends on the type, structure and geometry of the NPs. The high sensitivity of surface plasmon resonance peaks causes that core shell NPs be completely suitable for medical and optical biosensor applications.