Monolithically-integrated hybrid heterostructure diode laser with dielectric-film waveguide DBR

Abstract

In the monolithically-integrated hybrid (MIH) DBR diode laser, the five-layer Ga(Al)As-GaAs heterostructure waveguide of the gain region was monolithically butt-joined on a common GaAs substrate with a highly-transparent corrugated dielectric-film waveguide consisting of sputtered SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> , Ta <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> O <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf> , and evaporated (corrugated) As <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> S <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> layers. The laser operated with the first-order grating under the pulsed current pumping at 300 K. The efficient resonant mode conversion (70 percent in power) has been obtained at the interface between the heterostructure and dielectric waveguides. The fundamental transverse and single-longitudinal mode output emission was obtained up to 160 mW ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ith = 120</tex> mA) with external differential quantum efficiency <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\eta \simeq 32</tex> percent. The advantages of a dielectric-film waveguide DBR are demonstrated. The use of such a DBR results in a high degree of sidemode suppression and stability of the spectral position of the emission line under the temperature variation, the corresponding spectral shift being <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\lsim 0.01</tex> Å/K.