InGaAsP/InP buried crescent laser emitting at 1.3 μm with very low threshold current

Abstract
An InGaAsP/InP injection laser is described in which a crescent-shaped InGaAsP active region is completely embedded in InP by the etch-and-fill l.p.c. technique and a double current confinement scheme is incorporated with two reverse-biased p-n junctions on both sides of the active layer. The best laser has the very low threshold current of 28 mA c.w. at room temperature, and shows stable single-mode c.w. operation up to about twice the threshold current.