Ultranarrow-waveguide AlGaAs/GaAs/InGaAs lasers
Abstract
We have designed, fabricated and studied ultranarrow-waveguide heterostructure lasers emitting in the spectral range 1000 - 1100 nm. The lasers have been characterised by current - voltage, light - current, far-field intensity distribution and internal optical loss measurements. The ultranarrow-waveguide lasers have been shown to have a threshold current density of ∼75 A cm-2, internal quantum efficiency near 100 % and internal optical loss near the lasing threshold under 1 cm-1, which corresponds to the level of standard heterostructures. We have demonstrated the possibility of obtaining up to 5 W of output power in continuous mode and up to 30 W in pulsed mode, with a beam convergence (FWHM) of 17.8°. The slope of the internal optical loss as a function of pump current for the ultranarrow-waveguide lasers can be markedly lower than that in lasers with a standard design, but internal quantum efficiency drops to 40 % with increasing pump current. The use of barrier layers in ultranarrow-waveguide lasers makes it possible to substantially reduce the drop in internal quantum efficiency.
- Publication:
-
Quantum Electronics
- Pub Date:
- July 2019
- DOI:
- 10.1070/QEL16944
- Bibcode:
- 2019QuEle..49..661B
- Keywords:
-
- absorption coefficient;
- semiconductor laser;
- internal optical loss;
- pulsed pumping;
- energy barrier;
- ultranarrow waveguide