RESUMO
We report III-nitride vertical-cavity surface-emitting lasers (VCSELs) with buried tunnel junction (BTJ) contacts. To form the BTJs, GaN TJ contacts were etched away outside the aperture followed by n-GaN regrowth for current spreading. Under pulsed operation, a BTJ VCSEL with a 14 µm diameter aperture showed a lasing wavelength of 430 nm, a threshold current of â¼20 mA (12 kA/cm2), and a maximum output power of 2.8 mW. Under CW operation, an 8 µm aperture VCSEL showed a differential efficiency of 11% and a peak output power of â¼0.72 mW.
RESUMO
We demonstrate a III-nitride edge emitting laser diode (EELD) grown on a (2021) bulk GaN substrate with a GaN tunnel junction contact for hole injection. The tunnel junction was grown using a combination of metal-organic chemical-vapor deposition (MOCVD) and ammonia-based molecular-beam epitaxy (MBE) which allowed to be regrown over activated p-GaN. For a laser bar with dimensions of 1800 µm x 2.5 µm, without facet coatings, the threshold current was 284 mA (6.3 kA/cm2) and the single facet slope efficiency was 0.33 W/A (12% differential efficiency). A differential resistivity at high current density of 2.3 × 10-4 Ω cm2 was measured.
RESUMO
A high-brightness, droop-free, and speckle-free InGaN/GaN quantum well blue superluminescent diode (SLD) was demonstrated on a semipolar (2021¯) GaN substrate. The 447-nm emitting SLD has a broad spectral linewidth of 6.3 nm at an optical power of 123 mW. A peak optical power of 256 mW was achieved at 700 mA CW injection current. By combining YAG:Ce phosphor, SLD-generated white light shows a color-rendering index (CRI) of 68.9 and a correlated color temperature (CCT) of 4340 K. The measured frequency response of the SLD revealed a -3 dB bandwidth of 560 MHz, thus demonstrating the feasibility of the device for both solid-state lighting (SSL) and visible-light communication (VLC) applications.