M. Buda et al., Low-loss low-confinement GaAs-AlGaAs DQW laser diode with optical trap layer for high-power operation, IEEE PHOTON, 11(2), 1999, pp. 161-163
A low-confinement asymmetric GaAs-AlGaAs double-quantum-well molecular-beam
-epitaxy grown laser diode structure with optical trap layer is characteriz
ed. The value of the internal absorption coefficient is as low as 1.4 cm(-1
), while keeping the series resistance at values comparable with symmetrica
l quantum-well gradient index structures in the same material system. Uncoa
ted devices show COD values of 35 mW/mu m. If coated, this should scale to
about 90 mW/mu m, The threshold current density is about 1000 A/cm(2) for 2
-mm-long devices and a considerable part of it is probably due to recombina
tion in the optical trap layer. Fundamental mode operation is limited to 12
0-180 mW for 6.5-mu m-wide ridge waveguide uncoated devices and to 200-300
mW for 13.5-mu m-wide ones, because of thermal waveguiding effects, These v
alues are measured under pulsed conditions, 10 mu s/l ms.