Novel effect of thickness of separate confinement heterostructure layer

Experiments show that the layer of separate confinement heterostructure has a significant influence on the emission spectrum of semiconductor optical amplifiers/superluiminescent diodes. Reducing the thickness of layer of separate confinement heterostructure at p-side could improve the uniformity of carrier distribution among multiple quantum wells. With three In$_{0.67}$Ga$_{0.33}$As$_{0.72}$P$_{0.28}$ quantum wells near the n-side, when the thickness of the layer of separate confinement heterostructure changes from 120 nm to 30 nm, the operation current for semiconductor optical amplifiers/superluiminescent diodes to exhibit the full width at half maximum spectral width of above 270 nm could be reduced from 500 to 160 mA. The layer of separate confinement heterostructure is found to have a significant influence on the carrier distribution among the multiple quantum wells and the emission spectrum semiconductor optical amplifiers/superluminescent diodes.