High‐power fundamental mode AlGaAs quantum well channeled substrate laser grown by molecular beam epitaxy

We demonstrate a high‐power AlGaAs single quantum well graded‐index separate confinement heterojunction laser grown by molecular epitaxy over channeled substrates. Fundamental mode operation up to 130 mW for reflection modified devices has been achieved at a high differential quantum front‐facet efficiency of 81%. This device structure allows extremely low threshold currents to 6 mA for power lasers due to the incorporation of lateral current blocking pn junction by crystallographic plane‐dependent doping of amphoteric dopants. We obtained a very high‐power continuous‐wave fundamental mode operation of this type of laser at extremely low threshold currents and very high overall efficiency of more than 50%. This laser shows considerable potential for applications in optical storage and printer technology.