Fabrication of 1.3 μm wavelength InGaAsP/InP ridge overgrown distributed feedback laser diode

Abstract

InGaAsP/InP distributed feedback (DFB) laser emitting at 1.3um have been fabricated on material grown completely by LPE. An analysis of TE mode exclusively is presented for ridgewaveguide (or strip-loaded) DFB laser by the effective index method approximately. Second-order surface corrugation for 1.3um DFB lasers have been fabricated in InP and InGaAsP using holographic interference lithography and we have discussed that the mask/space ratio of 1:1 had an optimum DFB coupling strength using Fourier analysis of our grating profile. The growth steps permit post-active-layer growth determination of the grating period, and the fabrication of this laser is simple with an automatic alignment of the current confinement to the ridge-overgrowths, which form the strip-loaded waveguide the laser. The lateral overgrowth extending over the oxide films on both sides of the window stripe enhances the effect of grating feedback. LPE have been employed succesfully for ridge over-grown on the corrugated surface at a low temperature of $581\,^\circ\!C$ with a cooling rate of $0.51\,^\circ\!C/\min$.