InGaAs/GaAs 0.98- $\mu{\hbox {m}}$ Low-Divergence Central-Lobe Semiconductor Lasers With $\delta$

In this paper, we describe a new structure design for producing low-threshold, high-efficiency, and high-brightness 0.98-mum lasers. In this structure, we incorporated a self-discriminating weak optical confinement asymmetrical waveguide coupled to passive waveguides, and an active region based on three InGaAs quantum wells (QWs) coupled to Te n-type delta-doping. Optimized coupling between the delta-doping and the three QWs, together with waveguide optimization and doping profile optimization, yields J_th = 98 A/cm² per QW, T₀ = 80degC, and a far-field central lobe angle of ~10deg.