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Field intensity analysis of a GaN-based channel substrate planer blue-green laser diode has been carried out at a 507 nm wavelength for better optical confinement to explore its applicability in optical storage. Our analysis reveals that a thin active layer does not support higher order modes. However, an active layer thickness of 0.23 µm supports the fundamental transverse mode and mode 1. The change in the geometry of the channel region provides guiding effects along the X-direction in a structure. It was found that an increase in the channel depth causes an increase of the effective refractive index in a nonlinear manner and the confinement factor increases in a nonlinear manner with the active layer thickness. It is inferred from our analysis that an increase in aluminium mole fraction in the clad leads to an excellent confinement of near field intensity, which has been attributed to an increase of refractive index step. The full width at half maximum (FWHM) of near field intensity was found to be 0.35 and 0.31 µm corresponding to aluminium mole fractions of 5% and 15%, respectively. The near field intensity distribution in the channel waveguide (3D) along the X-and Y-directions clearly shows confinement at the centre of the active region.

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Mg x Zn 1−x O films with 0.15 mole composition of Magnesium were successfully deposited by the spin coating sol-gel method. Zinc acetate dihydrate and Magnesium acetate were used as starting precursors to prepare the solution in ethanol solvent. The MgZnO films were deposited on microscopic glass substrates and post annealed at three different temperatures. X-ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and UV-VIS Spectrophotometer were used to characterize the deposited films for studying structural and optical properties. Energy dispersive analysis by X-ray (EDAX) was used to determine incorporation of Mg content in ZnO films. XRD spectrum reveals that, the deposited Mg doped ZnO films were polycrystalline in nature. The intensity of c-axis in the XRD spectrum goes on decreasing as Mg composition slightly increasing corresponding to increase in annealing temperature. EDAX spectra clearly showed the incorporation of Mg into the ZnO films. Semiconductor characterization system was used for the I-V characterization of MgZnO films. I-V characteristics show decrease in current as increase in the biased voltage. Optical band gap of MgZnO films was found to be increased from 3.2 to 3.38 eV as estimated from the absorption coefficients.