Ultra-low threshold current density quantum dot lasers using the dots-in-a-well (DWELL) structure
نویسندگان
چکیده
Quantum dots laser diodes using the dots-in-a-well (DWELL) structure (InAs dots in an InGaAs quantum wells) have exhibited significant recent progress. With a single InAs dot layer in Inoi5Gao.8sAs quantum well, threshold current densities are as low as 26 A cm2 at 1 .25 xm. Quantum dot laser threshold current densities are now lower than any other reported semiconductor laser. In this work, the threshold current density is reduced to 1 6 A cm2 by HR coatings on the same device. Further investigation of performance reveals that use of multiple DWELL stacks improves the modal gain and internal quantum efficiency. It is suggested that carrier heating out of the quantum dots limits the T0 value of these DWELL lasers.
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