Red and cyan leds for data transmission over 1 mm POF using pulse amplitude modulation

Results on the data transmission over a polymer optical fiber with R&D samples of cyan GaN LEDs operating at 475 nm are reported in this paper. The performance of a commercially available Resonant Cavity LED (RC-LED) operating at 655 nm is shown as a reference. The data transmission over the different POF distances was investigated using both Non Return to Zero (NRZ) and Pulse Amplitude Modulation (PAM) modulation schemes. 1.2 Gbit/s and 1.9 Gbit/s transmission using NRZ modulation and post-processed decision feed-back equalization (DFE) was realized over a 50 m SI-POF link at BER of 10^-3 using cyan GaN LED and red light source respectively. At shorter link distances up to 20 m the cyan LEDs provide a better data transmission performance. For distances above 20 m the chromatic dispersion of the fiber in the short wavelength range reduces the potential of the system based on GaN LED due to its wide spectral width of 35 nm. The behaviour of the chromatic dispersion was investigated. The performance of the LEDs at different temperatures was tested.