High Performance InAs/${\rm In}_{0.53}{\rm Ga}_{0.23}{\rm Al}_{0.24}{\rm As}$/InP Quantum Dot 1.55 $\mu{\rm m}$ Tunnel Injection Laser

Abstract

The characteristics of 1.55 μm InAs self-organized quantum-dot lasers, grown on (001) InP substrates by molecular beam epitaxy, have been investigated. Modulation doping of the dots with holes and tunnel injection of electrons have been incorporated in the design of the active (gain) region of the laser heterostructure. Large values of To=227 K (5 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C ≤ T ≤ 45 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> C) and 100 K were derived from temperature dependent measurements of the light-current characteristics. The modal gain per dot layer is 14.5 cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> and the differential gain derived from both light-current and small-signal modulation measurements is ~ 0.8×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-15</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The maximum measured -3 dB small-signal modulation bandwidth is 14.4 GHz and the gain compression factor is 5.4×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-17</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The lasers are characterized by a chirp of 0.6 Å for a modulation frequency of 10 GHz and a near zero α-parameter at the peak of the laser emission. These characteristics are amongst the best from any 1.55 μm edge-emitting semiconductor laser.