Stimulated emission in the heavily doped Al-=SUB=-0.68-=/SUB=-Ga-=SUB=-0.32-=/SUB=-N : Si structures with transverse optical pumping at room temperature

Abstract

The broadband stimulated emission in the spectral range λ=380-700 nm with the inhomogeneous broadening has been experimentally obtined in the heavily doped Al0.68Ga0.32N : Si structures grown by molecular beam epitaxy. The behavior of the intensities and spectra of stimulated emission from the edge of the active element with transverse pulsed pumping by radiation with λ=266 nm, measured at room temperature, demonstrate the threshold behavior and optical gain. For stimulated emission with a maximum at λ=500 nm, the minimum threshold pump power density was 6.5 kW/cm2 for excited region length of 1.5 mm. The parameters and contributions of the two main processes e-A and D-A of radiative recombination in the excited structures for stimulated emission and optical gain are studied. Keywords: stimulated emission, heavily doped AlxGa1-xN structures, luminescence, optical gain, donor-acceptor recombination.