Internally wavelength stabilized 910 nm diode lasers with epitaxially stacked multiple active regions and tunnel junctions

Abstract

We present a multi‐active‐region bipolar‐cascade distributed‐Bragg reflector (DBR) laser emitting around 910 nm. The three active regions and two tunnel junctions are located in a single waveguide core sharing the same third‐order vertical mode. A slope efficiency of 2.25 W/A was measured with a threshold current density of 400 A/cm2. Due to the implemented 7th Bragg order surface grating, the laser exhibits a narrow optical spectrum with a width of 0.3 nm and a thermal detuning of 60 pm/K.

Epitaxially-Stacked High Efficiency Laser Diodes Near 905 nm

“…The intrinsic parameters, such as the effective mass of electrons (me) and holes (mh), were modified as me=0.09 and mh=0.53 to match the measured value of the peak current density for the ndoping concentration of 4.0×10 19 cm -3 . The experimental Jp improved from 2.8×10 3 to 7.7×10 3 A/cm 2 , with the n-doping concentration increasing from 4×10 19 to 6×10 19 cm -3 . The simulated n-doping concentrations of 5.0×10 19 and 6.0×10 19 cm -3 were adjusted to the value of 4.65×10 19 and 4.80×10 19 cm -3 , respectively, to match Jp with the experimental results.…”

“…The experimental Jp improved from 2.8×10 3 to 7.7×10 3 A/cm 2 , with the n-doping concentration increasing from 4×10 19 to 6×10 19 cm -3 . The simulated n-doping concentrations of 5.0×10 19 and 6.0×10 19 cm -3 were adjusted to the value of 4.65×10 19 and 4.80×10 19 cm -3 , respectively, to match Jp with the experimental results. Both simulation and experimental results demonstrate that Jp improves significantly with increasing doping concentration.…”

“…The TJ test structures were epitaxially grown on an n-GaAs substrate with a 500 nm n-GaAs buffer layer (3×10 18 cm -3 ), a 25 nm Te-doped n++ GaAs with various doping concentrations of 4×10 19 , 5×10 19 , and 6×10 19 cm -3 , a 25 nm C-doped p++ GaAs (1×10 20 cm -3 ) and finalized with p++ GaAs contact layer (p>5×10 19 cm -3 ). Since the p-doping reaches a high level of 1×10 20 cm -3 with a C dopant, we focus on investigating the ndoping concentration optimization using the Te dopant.…”

Wavelength-stabilized ns-pulsed 2.2 kW diode laser bar with multiple active regions and tunnel junctions

“…Compared to the single-active region laser bar, the optical power is enhanced by a factor of 2.9 determined at 1 kA and 25 • C. The enhancement factor decreases to 2.8 at a current of 800 A, revealing a stronger power saturation of the single-active region laser bar. The result shows that the in-house electronic driver can successfully be used here as it is capable of providing also the higher chip voltages required for the three-active region lasers [12,13].…”

“…The grating is dry-etched into the p-side in parts of the completely grown wafer [14]. More details on the layer structure and the surface grating can be found in [12,13]. Broad-area lasers were then fabricated using a standard process that includes dry etching of trenches for lateral optical confinement, fol- lowed by SiN deposition, opening the insulator between the trenches, metalization with Ti-Pt-Au as the p-electrode, thinning of the substrate, and deposition of Ni-Au-Ge as the n-electrode [13].…”