Near field intensity and mode confinement analysis in gan based blue laser diode at 507 nm wavelength

Abstract

One of the most promising blue laser diode structures is GaN / AlGaN heterostructure, which provides effective carrier and optical confinement. We have carried out analysis of GaN based channel substrate planer blue laser diode at 507 nm wavelength for better optical confinement to explore its applicability in optical storage. Our analysis reveals that higher order modes are not supported by thin active layer. However, active layer thickness of 0.23 micron supports fundamental transverse mode and mode 1. The change in geometry of channel region provides lateral guiding effects in a structure. It was found that an increase in channel depth causes increase of effective refractive index in non-linear manner. It is inferred from our analysis that an increase in Aluminium mole fraction in 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 micron corresponding to Aluminium mole fractions of 5% and 15% respectively. Near field intensity distribution in channel waveguide (3D) along X and Y directions clearly shows confinement at the center of the active region.One of the most promising blue laser diode structures is GaN / AlGaN heterostructure, which provides effective carrier and optical confinement. We have carried out analysis of GaN based channel substrate planer blue laser diode at 507 nm wavelength for better optical confinement to explore its applicability in optical storage. Our analysis reveals that higher order modes are not supported by thin active layer. However, active layer thickness of 0.23 micron supports fundamental transverse mode and mode 1. The change in geometry of channel region provides lateral guiding effects in a structure. It was found that an increase in channel depth causes increase of effective refractive index in non-linear manner. It is inferred from our analysis that an increase in Aluminium mole fraction in 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 mi...