Frequency division multiplexing using high radiance 800-nm light-emitting diodes

The use of junction current confinement high radiance light-emitting diodes for frequency division multiplexing of up to 14 analog television signals is examined by measuring cross modulation and composite triple beat. Fourteen channel transmission distance is limited to 0.3 km by chromatic and modal dispersion for typical 100-μm core graded index fiber. Most diodes were capable of 50-percent zero-to-peak current modulation depth at 80-mA drive before exceeding -48-dB cross-modulation (XMOD) distortion (2 channels). Increasing the number of channels decreases the distortion level for a fixed zero-to-peak current modulation depth.