High-Speed GaN-Based Green Light-Emitting Diodes With Partially n-Doped Active Layers and Current-Confined Apertures

We demonstrate a high-speed GaN-based green light-emitting diode for plastic optical fiber (POF) communication applications. By using a combination of n-type doping and undoped In_xGa_1-xN/GaN based multiple quantum wells (MQWs), and a 76-mum-diameter current-confined aperture structure, we can obtain an extremely high electrical-to-optical (E-O) 3 dB bandwidth (~330 MHz), which is limited by the spontaneous recombination lifetime of the MQWs. A reasonable coupled power (-264 muW) can be simultaneously achieved for a 2 mm in diameter POF with a 0.5 numerical aperture (NA).