Epitaxially-Stacked High Efficiency Laser Diodes Near 905 nm

Abstract

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 simulation 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. Triplecavity 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.

High brightness nanosecond-pulse operation of 905 nm distributed Bragg reflector tapered-ridge-waveguide lasers with multiple active regions

“…However, to achieve high pulse powers and a good beam propagation ratio (M² < 5) remains a challenge. A means to achieve high output power of a diode laser is to epitaxially stack N independent diode lasers where each diode laser features its own vertical waveguide [4][5][6][7][8]. Alternatively, as we introduced previously, multiple active regions alternating with tunnel junctions can be epitaxially stacked in a common higher-order vertical waveguide where the mode order N-1 is determined by the number of active regions N [9,10].…”