GaN Light-Emitting Diodes for up to 5.5-Gb/s Short-Reach Data Transmission Over SI-POF

We report a high-speed data transmission over a 1-mm diameter step-index polymer optical fiber (SI-POF) with GaN light-emitting diodes (LEDs) operating at 435 and 475 nm. The modulation bandwidths of the LEDs at 40 mA were 180 and 300 MHz, respectively. A maximum bit rate of 5.5 Gb/s was achieved with a 475-nm GaN LED at -1.8-dBm fiber-coupled power over a 1-m SI-POF employing 4-pulse-amplitude modulation format. Compared with the performance of a high-speed red resonant-cavity LED under the same test setup, the chromatic dispersion reduces the potential of the GaN LED-based system when the transmission distance is longer than 30 m.