High characteristic temperature (T 0 =243 K) of stacked InGaAs quantum wire lasers grown on (775)B GaAs substrates by molecular beam epitaxy

Stacked In 0.15 Ga 0.85 As quantum wire (QWR) laser structures were grown on (775)B-oriented GaAs substrates by molecular beam epitaxy. The laser active region consists of three 2.4-nm-thick QWR layers separated by thin (0.5 or 1 nm thick) AlAs barriers. It showed better one-dimensionality than that of nonstacked (775)B QWRs. The stacking (775)B QWR lasers oscillated at room temperature with the threshold current density of about 3 kA/cm 2 under the pulsed current condition. They showed the characteristic temperature of T 0 ∼243 K in the temperature range of 20–80 °C, which is very high not only T 0 values of previous (775)B QWR lasers but also among those of the low-dimensional quantum structure lasers reported so far.