Author(s): Qiu, YQ (Qiu, Ya-Qi); Lv, ZR (Lv, Zun-Ren); Wang, H (Wang, Hong); Wang, HM (Wang, Hao-Miao); Yang, XG (Yang, Xiao-Guang); Yang, T (Yang, Tao)

Source: AIP ADVANCES Volume: 11 Issue: 5 Article Number: 055002 DOI: 10.1063/5.0044313 Published: MAY 1 2021

Abstract: We report on the significantly improved linewidth enhancement factor (alpha(H)-factor) of 1.3-mu m InAs/GaAs quantum dot (QD) lasers by direct Si doping, compared with ones having identical structures but without the Si doping. It is found that the alpha(H)-factors for the ground-state and first excited-state at their gain peak positions of the Si-doped QD lasers are 1.48 and 0.63 while those of the undoped QD lasers are 2.07 and 1.07, greatly decreasing by about 28.5% and 41.1%, respectively. Furthermore, theoretical calculation and analysis suggest that direct Si doping would increase the electron quasi-Fermi level in conduction, leading to the increase in population inversion. Meanwhile, the appearance of a built-in electric field caused by the Si doping would accelerate the capture of electrons into QDs and strengthen the confinement effect of electrons, resulting in an increased differential gain.

Accession Number: WOS:000646355400015

eISSN: 2158-3226

Full Text: https://aip.scitation.org/doi/10.1063/5.0044313