Epitaxially-Stacked High Efficiency Laser Diodes Near 905 nm

We report on studying tunnel junctions and an optical cavity structure for developing epitaxially-stacked high-efficiency 905 nm high-power laser diodes. The GaAs tunnel junctions were explored via simulations and experiments to realize a high peak current density of 7.7 × 10
⁴
A/cm
²
and a low specific resistance of 1.5 × 10
⁻⁵
Ωcm
²
with a high n-doping concentration of 6 × 10
¹⁹
cm
⁻³
. Employing a low-loss epitaxial structure design, single-, double-, and triple-cavity structure laser diodes demonstrated power scaling by epitaxial stacking. Triple-cavity laser diodes have a low optical loss (0.42 cm
⁻¹
) and generate a peak power of 83 W with a short cavity length of 750 μm at a limited current of 30 A.