Room-temperature 2.2-μm InAs-InGaAs-InP highly strained multiquantum-well lasers grown by gas-source molecular beam epitaxy

We report the fabrication and performances of 2.2-μm InAs-InGaAs-InP highly strained multiple-quantum-well (MQW) lasers grown by gas-source molecular beam epitaxy. The lasers operated at room temperature demonstrate a threshold current density of 900 A/cm² a maximum external quantum efficiency of 28%, and a maximum output power exceeding 60 mW per facet. To the best of our knowledge, this is the longest room-temperature emission wavelength reported for lasers grown on InP substrates to date. The effect of strain compensation on the quality of the InAs-In_xGa_1-xAs MQW´s was also studied using double crystal X-ray diffractometry and photoluminescence techniques. The experimental results reveal that there is no significant difference on the epilayer quality of the samples with strain compensation. However, the group V stable surface growth condition is indeed better than the group III stable surface growth condition on the epilayer quality