Low-bias-current direct modulation up to 33 GHz in InGaAs/GaAs/AlGaAs pseudomorphic MQW ridge-waveguide lasers

Abstract

Modulation bandwidths of 24 GHz (I/sub bias/=25 mA) and 33 GHz (I/sub bias/=65 mA) are demonstrated for 3×100 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> In/sub 0.35/Ga/sub 0.65/As/GaAs multiple quantum well ridge-waveguide lasers with undoped and p-doped active regions, respectively. These performance enhancements have been achieved both by lowering the growth temperature of the high-Al-mole-fraction cladding layers and by utilizing short-cavity devices, fabricated with dry-etched facets using chemically-assisted ion-beam etching. Both the undoped and p-doped lasers also demonstrate modulation current efficiency factors exceeding 5 GHz/mA <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> 2/, the best reported results for any semiconductor laser.