Negative Characteristic Temperature of InGaAs Quantum Dot Injection Laser

Abstract

The range of negative characteristic temperatures in temperature dependences of threshold current density of low-threshold (In, Ga)As/(Al, Ga)As quantum dot injection lasers has been observed. A model describing the decrease in threshold current density with temperature at low temperatures is proposed.

Effects of spontaneous emission rates on lasing characteristics of long-wavelength (1.3 µm) GaAs-based quantum dot lasers

“…The shift from multi-mode toward single-mode operation marks the transition from carrier recombination in isolated QDs to carrier recombination in a thermally coupled ensemble. 9 At the highest temperature measured, T = 324K, the spectrum is narrower yet, showing that the transition to a thermal gain distribution occurs over a wide range of temperatures. Fig.…”

Device Characteristics of Low-Threshold Quantum-Dot Lasers

“…6), i.e., these low-threshold QD lasers have a negative characteristic tem perature. This unusual behavior is associated with the lack of an equilibrium dot population at low temperatures, 19 since the thermal evaporation of carriers out of QDs is strongly suppressed at low temperatures due to its phonon-induced nature. There exists some boundary temperature, which separates the regions of the equi librium and non-equilibrium populations of QDs.…”

“…Low-threshold injection lasers based on self-organized QDs have been already created and preliminary studied in many of the above material systems. [15][16][17][18][19][20][21][22] This paper is organized as follows. In Sec.…”

EXTENDED WAVELENGTH (1.0 TO 1.3 μm) InGaAs/GaAs QUANTUM DOT GaAs-BASED VERTICAL-CAVITY SURFACE-EMITTING AND LATERAL-CAVITY EDGE-EMITTING LASERS

“…(1). Equilibration between QDs within the ensemble that leads to a negative temperature characteristic can also be treated, 55 but is not included here.…”