Dependence of lasing wavelength on optical loss in quantum dot laser

The dependence of the lasing line position on optical loss is investigated for stripe lasers with different numbers of planes of dense InGaAs/GaAs quantum dots (quantum well-dots). An analytical expression is obtained that explicitly establishes the relationship between the peak position of the gain spectrum and the value at the peak gain for an array with a Gaussian density of states. Reasonable agreement between the model predictions and experimental data is demonstrated. The saturated mode gain is estimated as 51 cm$^{-1}$ per layer.