Linear Gain of Si Quantum Dot laser

Abstract

Linear Gain spectra of  undoped and doped QD laser are studied under the inhomogeneous broadening assumption for four the height disc quantum dot laser are (h=0.2,h=0.5,h=1,h=1.5) the disc height QDL size effect on the gain, .the wavelength and the linear  gain increase obtained by increase QDL size height and so four the radius at quantum dot are (ρ=8 nm, ρ=10 nm, ρ=12 nm, ρ=16 nm) . we show that disc radius QDL size effect on gain-wavelength relation where at increase QDL radius (ρ=16 nm) the gain lower and shift wavelength amount (15 nm) to right. . We studied   at four  mole concentration  for WL (barrier layer) The  different concentrations in the SiOx WL layer (mole fractions in the WL), the gain for four  -mole fractions, The gain peak reduced and shifted to down (absorption) for tow curve (green solid line and black solid line) with increasing SiOx concentration in the WL. The gain for the doped structures doubles the undoped ones. The gain increases while the wavelength is reduced with increasing Cd content due to the broader band discontinuity between QD states. These visible bands are essential in different applications. The effect of QD size effect is also examined. The wavelength is extended by  for each  QD height increment.

Received: 2025-07-23

Revised: 2025-08-23

Accepted: 2025-09-06