Ridge waveguide distributed feedback lasers with electron beam defined gratings

Abstract

We describe a ridge waveguide distributed feedback laser operating at λ=1.5 μm. The ridge waveguide has been formed by liquid phase epitaxial overgrowth over a dielectric-defined narrow stripe. Second order diffraction gratings have been written using electron beam writing and transferred by reactive ion milling. cw threshold currents of these lasers vary from 80 to 150 mA and single mode operation over a temperature range of 60 °C has been demonstrated. Even under 1-GHz modulation the Bragg mode intensity is at least 3000 times greater than that of the residual Fabry–Perot modes.