Graded doping low internal loss 1060-nm InGaAs/AlGaAs quantum well semiconductor lasers

Internal loss is a key internal parameter for high power 1060-nm In Ga As/Al Ga As semiconductor laser.In this paper,we discuss the origin of internal loss of 1060-nm In Ga As/Ga As quantum well(QW) Al Ga As separate confinement heterostructure semiconductor laser,and the method to reduce internal loss.By light doping the n-cladding layer,and stepwise doping the p-cladding layer combined with the expanded waveguide layer,a broad area laser with internal loss of 1/cm is designed and fabricated.Ridge waveguide laser with an output power of 350 m W is obtained.The threshold current and slope efficiency near the threshold current are 20 m A and 0.8 W/A,respectively.