Low threshold InAs/InP quantum dot lasers

InAs/InP quantum dot (QD) lasers are promising light sources for optical communication due to their discrete energy states, offering advantages such as low threshold current density and enhanced thermal stability. However, challenges remain in achieving uniform QDs on the InAs/InAlGaAs/InP material system to ensure low threshold current density and high-temperature operation. This work demonstrates low threshold, high-temperature L-band InAs/InAlGaAs/InP QD lasers grown on InP (001) substrates with the indium-flush technique to optimize QD uniformity. The as-cleaved seven-stack QD lasers under pulsed injection exhibit a very low threshold current density of 69 A/cm² per QD layer and achieve a high maximum operating temperature of 130 °C. These results represent significant progress in InAs/InP QD laser development, highlighting the potential for high-performance semiconductor light sources in optical communication.