Cavity length and stripe width dependent lasing characteristics of InAs/InP(1 0 0) quantum dot lasers

• Multi-peak lasing relying on the size of InAs/InP QD laser was observed.
• The output power and threshold current density of QD laser had strong connection with cavity width.
• The shorter cavity of QD laser had a wide tunable region in external cavity system.

The lasing characteristics of InAs/InP(1 0 0) quantum dot lasers grown by gas source molecular beam epitaxy were carefully studied by varying cavity length and stripe width. With the increase of injection current, the lasers having a longer cavity length and a wider stripe width exhibited simultaneously two-lasing peaks or/three-lasing peaks. The high-energy peak undergoes continuous buleshift, while the low-energy peaks are somewhat fixed. At the same times, the injection current density decreased as the stripe width increase. When the lasers were applied to external cavity system, the shorter cavity length of InAs/InP quantum dot laser had a wider tunable range.