Low threshold current density and high power InGaN-based blue-violet laser diode with an asymmetric waveguide...

Performance of InGaN-based blue-violet laser diodes (LD) with different waveguide structure were investigated by simulation and experimental methods. Theoretical calculation demonstrated that threshold current (I_th) can be reduced and slope efficiency (SE) can be improved by using an asymmetric waveguide structure. Based on the simulation results, a LD with 80-nm-thick In_0.03Ga_0.97N lower waveguide (LWG) and 80-nm-thick GaN upper waveguide (UWG) is fabricated with flip chip package. Under continuous wave (CW) current injection at room temperature, its optical output power (OOP) reaches 4.5 W at an operating current of 3 A and the lasing wavelength of 403 nm. The threshold current density (Jth) is 0.97 kA/cm² and the SE is about 1.9 W/A.