Title :
Highly efficient grating-coupled surface-emitters with single outcoupling elements
Author :
Eriksson, N. ; Hagberg, M. ; Larsson, A.
Author_Institution :
Dept. of Optoelectron. & Electr. Meas., Chalmers Univ. of Technol., Goteborg, Sweden
Abstract :
We demonstrate highly efficient grating coupled surface emitting lasers with single-grating outcouplers. An outcoupling efficiency of 94% into air was achieved using a nonresonant rectangular second-order grating in combination with a multilayer reflector below the waveguide. This resulted in an external differential quantum efficiency as high as 50%, comparable to that of conventional edge-emitting lasers, limited by absorptive loss in the passive grating sections. The lasers have separated oscillators and outcouplers, which facilitates the fabrication of surface emitters that possess beam-shaping capabilities through holographic wavefront conversion.
Keywords :
III-V semiconductors; diffraction gratings; gallium arsenide; holographic optical elements; indium compounds; laser beams; laser cavity resonators; optical couplers; optical fabrication; optical films; quantum well lasers; reflectivity; surface emitting lasers; waveguide lasers; 50 percent; 94 percent; InGaAs; InGaAs quantum well lasers; absorptive loss; beam-shaping capabilities; edge-emitting lasers; external differential quantum efficiency; grating coupled surface emitting lasers; highly efficient grating-coupled surface-emitters; holographic wavefront conversion; multilayer reflector; nonresonant rectangular second-order grating; outcoupling efficiency; outcoupling elements; passive grating sections; single-grating outcouplers; surface emitters; Gratings; Holography; Nonhomogeneous media; Optical coupling; Optical device fabrication; Oscillators; Rectangular waveguides; Surface emitting lasers; Surface waves; Waveguide lasers;
Journal_Title :
Photonics Technology Letters, IEEE
