Optoelectronic and Birefringence Properties of Weakly Mg Doped ZnO Thin Films Prepared by Spray Pyrolysis

MgxZn1−xO thin films were deposited on glass substrate with x varied between 0.01 and 0.05 by spray pyrolysis at a temperature of 450 °C. The structural investigation showed that all thin films had ZnO wurtzite structure with a preferred (002) orientation. The gap energy was calculated using Tauc’s plot and it decreased over the Mg content by 0.07 eV. The charge carriers’ density dropped by an order of 105 as Mg content increased whereas the resistivity and the mobility increased. SEM observations revealed a significant difference between undoped and doped thin films. A 632.8 nm laser source prism coupler revealed 2 optical modes for every thin film in each Transverse Electric and Transverse Magnetic mode, the birefringence of the Mg doped films was positive. Both ordinary and extraordinary refractive indexes were found to decrease as the Mg content increased. Great intention has been paid to the relation between the refractive, charge carriers density and the optical band gap.

Optoelectronic and Birefringence Properties of Weakly Mg Doped ZnO Thin films Prepared By Spray Pyrolysis.

MgxZn1−xO thin films were deposited on glass substrate with x varied between 0.01 and 0.05 by spray pyrolysis at a temperature of 450 °C. The structural investigation showed that all thin films had ZnO wurtzite structure with a preferred (002) orientation. The gap energy was calculated using Tauc’s plot and it decreased over the Mg content by 0.07 eV. The charge carriers’ density dropped by an order of 105 as Mg content increased whereas the resistivity and the mobility increased. SEM observations revealed a significant difference between undoped and doped thin films. A 632.8 nm laser source prism coupler revealed 2 optical modes for every thin film in each Transverse Electric and Transverse Magnetic mode, the birefringence of the Mg doped films was positive. Both ordinary and extraordinary refractive indexes were found to decrease as the Mg content increased. Great intention has been paid to the relation between the refractive, charge carriers density and the optical band gap.

Vector optomechanical entanglement

The polarizations of optical fields, besides field intensities, provide more degrees of freedom to manipulate coherent light–matter interactions. Here, we propose how to achieve a coherent switch of optomechanical entanglement in a polarized-light-driven cavity system. We show that by tuning the polarizations of the driving field, the effective optomechanical coupling can be well controlled and, as a result, quantum entanglement between the mechanical oscillator and the optical transverse electric mode can be coherently and reversibly switched to that between the same phonon mode and the optical transverse magnetic mode. This ability to switch optomechanical entanglement with such a vectorial device can be important for building a quantum network being capable of efficient quantum information interchanges between processing nodes and flying photons.

Tilted Nano-Grating Based Ultra-Compact Broadband Polarizing Beam Splitter for Silicon Photonics

An ultra-compact broadband silicon polarizing beam splitter is proposed based on a tilted nano-grating structure. A light cross coupling can be realized for transverse-magnetic mode, while the transverse-electric light can almost completely output from the through port. The length of the coupling region is only 6.8 μm, while an extinction ratio of 23.76 dB can be realized at a wavelength of 1550 nm. As a proof of concept, the device was fabricated by a commercial silicon photonic foundry. It can realize a 19.84 dB extinction ratio and an 80 nm working bandwidth with an extinction ratio of larger than 10 dB. The presented device also shows a good fabrication tolerance to the structure deviations, which is favorable for its practical applications in silicon photonics.

Design of New Convex Lens Shaped Y Splitter for better Optical Communication

This Paper describes, a photonic crystal waveguide based a Y-splitter. The outcomes of this Y-splitter are fixed by mechanisms of plane wave augmentation and Finite Difference Time Domain (FDTD). A lattice structure of hexagon shape is chosen as a basis for the formation of waveguide structure for the designing of Y-splitter. Subsequently, the calculation of power in transverse magnetic mode in equivalent the power calculated of the dual output ports of the proposed device.; the proposed device design of the splitter dispenses moderately greater transmission efficiency. This is affirmed by the simulation results obtained from the work done. The splitting ratio for both the halves was almost at 46%, and the aggregate radiation loss was confirmed to be almost 8 % for each output port. Therefore, the suggested Y-splitter is estimated as a better and more efficient as compare to basic splitter and ASS modified splitter.

Dispersion Characteristics of Electromagnetic Wave in Magnetized One Dimensional Ferrite Photonic Crystals with Mixed Field Configuration

The dispersion characteristics and phase index of electromagnetic waves in two types of magnetized one dimensional ferrite photonic crystals with mixed field configuration are studied for transverse magnetic mode. The dispersion equation and formula for phase index are derived using transfer matrix method. It is found that in type-1 & type-2 magnetized one dimensional ferrite photonic crystals, photonic band gaps (PBGs) show dependence on HOYIG and HONI respectively. The PBGs corresponding to thinner YIG layer are at higher frequency side at fixed. The variation of frequency-filling factor shows that PBGs occur in the form of lobe for both types. It is observed that the phase index is strongly influenced by external magnetic fields, and filling factor. It is demonstrated that PBGs in phase index occur in the form of lobes at fixed. Also, with decrease in the magnitude of phase index, number of lobe increases. The phase index, field and frequency plots show that there are multiple peaks in the PBGs of phase index in the lower frequency.

EMT simulation and effect of TTI anisotropic media in EMT signal

An axisymmetric finite difference method is employed for the simulations of electromagnetic telemetry in the homogeneous and layered underground formation. In this method, we defined the anisotropy property using extensive 2D conductivity tensor and solved it in the transverse magnetic mode. Significant simplification arises in the decoupling of the anisotropic parameter. The developed method is cost-efficient, more straightforward in modeling anisotropic media, and easy to be implemented. In addition, we solved the integral operation in the estimation of measured surface voltage using Gaussian quadrature technique. We performed a series of numerical modeling of EM telemetry signals in both isotropic and anisotropic models. Experiment with 2D tilt transverse isotropic media characterized by the tilt axis and anisotropy parameters shows an increase in the EMT signal with an increase in the angle of tilt of the principal axis for a moderate coefficient of anisotropy. We show that the effect of the tilt of the subsurface medium can be observed with sufficient accuracy and that it is an order of magnitude of 5 over the tilt of 90 degrees. Lastly, consistent results with existing field data were obtained by employing the Gaussian quadrature rule for the computation of surface measured signal.

Analytic modelling of a planar Goubau line with circular conductor

Planar Goubau lines show promise as high frequency, low-loss waveguides on a substrate. However, to date only numerical simulations and experimental measurements have been performed. This paper analytically investigates the surface wave mode propagating along a planar Goubau line consisting of a perfectly conducting circular wire on top of a dielectric substrate of finite thickness but infinite width. An approximate equation for the propagation constant is derived and solved through numerical integration. The dependence of the propagation constant on various system parameters is calculated and the results agree well with full numerical simulations. In addition, the spatial distribution of the longitudinal electric field is reported and excellent agreement with a numerical simulation and previous studies is found. Moreover, validation against experimental phase velocity measurements is also reported. Finally, insights gained from the model are considered for a Goubau line with a rectangular conductor. The analytic model reveals that the propagating mode of a planar Goubau line is hybrid in contrast to the transverse magnetic mode of a classic Goubau line.