本論文針對用於短距離光纖通訊綠光波段(520nm)之高速發光二極體研究及製作。我們採用阻障層(barrier)有矽(Si)摻雜及無摻雜之複合結構來製作氮化鎵/氮化銦鎵(GaN/InGaN)多重量子井(MQW)試片,以及使用具有76μm直徑之電流侷限結構。由量測結果發現此結構具有330MHz極佳的電-光(electrical-to-optical) 3-dB頻寬,此調制速度被多重量子井的自發性複合生命時間(spontaneous recombination lifetime)所限制。一個合理的264μW耦光功率也被同時的實現在2mm直徑、0.5數值孔徑(numerical aperture)的塑膠光纖上。
We demonstrate a high-speed GaN based Light-Emitting-Diode (LED) at a wavelength of around 520nm for the application to plastic optical fiber (POF) communication. By using a combination of n-type doping and undoped InxGa1-xN/GaN based multiple-quantum-wells (MQWs), and a 76μm in diameter current-confined aperture structure we can obtain an extremely high electrical-to-optical (E-O) 3-dB bandwidth (~330MHz), which is limited by the spontaneous recombination lifetime of the MQWs. A reasonable coupled power (~185μW) can be simultaneously achieved for a 2mm in diameter POF with a 0.5 numerical aperture (N.A.).