Prospects of highly efficient AlGaInP based surface emitting type ring-LED for 50 and 156 Mb/s POF data link systems

The detail design and performance of the surface emitting type visible light emitting diode (LED) is described for using in the plastic optical fiber (POF)-based data links. The diode showed brightness as high as 3.5 mW@100 mA (dc) and also exhibited the beam divergence angle as low as 10/spl deg/ with using of well designed plastic lens. The using of LED with plastic lens helps to attain also the coupling efficiency over 70% with POF. The temperature rise of the ring LED under operation is also estimated to be 9 and 6/spl deg/C less than the conventional diode at 50 and 35 mA bias currents, respectively. Transmission experiments reveal that the diode is suitable for 50 and 156 Mb/s 100 m POF-based data links.