Injection InGaAsP/lnP lasers with a threshold current density of 0.5 kA/cm2 at 300 K
Double-sided heterostructures with a three-layer waveguide including a thin (of thickness less than 0.1 μ) narrow-gap active layer were formed by the liquid epitaxy method on p-type InP substrates. The threshold current density in high-Q four-sided cavities was reduced to 512 A/cm2 at room temperature and continuous emission was observed from broad-area diodes.