Studying the change in inclination and semi-major axis of the satellites for low earth orbits

The main point of this paper is to evaluate the change in the inclination (i) and semi-major axis (a) due to tidal perturbation in orbital elements of a low Earth orbiting satellite LEO's. The orbital elements in the sense of Keplerian motion are affect perturbation in a satellite motion and change in the orbital elements must be employed to study the perturbations of the tidal effect on these satellites. These elements remain constant in the absence of perturbation where perturbed equation of motion was numerically integrated using Lagrange’s formulas where numerical analysis is the most suitable method to analyze disturbances. The findings demonstrate that the tidal disruption of the orbital elements relies on the satellite's inclination the variation in the ratio (∆i/i) and (∆a/a) decreases with increasing the inclination of satellite, while it increases with increasing the time and the difference in inclination reduces as the satellite's inclination rises, and the difference in semi major axis increases as time increases

Studying the light current characteristics of VCSEL by changing oxide confinement aperture

GaAs-based VCSELs with oxide-confined (OC) are performed by using fine selective radial “oxidation of AlAs-rich (AlGaAs) layers” from outside to the device axis leaving the central part unaffected. Such oxide apertures produced inside the cavities enhance the radial confinements related to current spreading and to a field that is optical altogether. A Modern design with a single fundamental mode is proposed to reduce threshold current operation to the extent of higher output by using the two OC VCSELs. Both of the oxide apertures were added to the node position of the resonator standing wave. Then, the diameters of together apertures can be adjusted independently giving VCSEL design an extra degree of freedom that allows optimization. It found that when both apertures had a radius of 4.2 µm, the low threshold current operation at a higher extent output is achieved with a single fundamental mode