Comment on “Theory and Experiment of ${\hbox{In}}_{1-{x}}{\hbox {Ga}}_{x}{\hbox {As}}_{y}{\hbox{P}}_{1-{y}}$ and ${\hbox{In}}_{1-{x}-{y}}{\hbox {Ga}}_{x}{\hbox {Al}}_{y}{\hbox {As}}$ Long-Wavelength-Strained Quantum-Well Lasers”