High-power, low-threshold, single-mode GaInAsP/InP laser by low-temperature, single-step liquid phase epitaxy

A GaInAsP/InP laser (λg=1.3 μm) on grooved substrate with a lens-shaped active layer, in which the current blocking junction is grown exclusively outside of the groove, has been fabricated by single-step liquid phase epitaxy. This technique is based on the preferential growth effects of InP and GaInAsP on the (100) oriented substrate with [011̄] directed grooves. Under cw operation, low threshold current (38 mA), high output power (40 mW/facet), and high external differential quantum efficiency (56%) are accomplished; fundamental transverse mode operation up to an output of 30 mW/facet is verified. These successful characteristics are realized by the introduction of the inner current confining layer.