Recent experiments using LEDs and single-mode fiber demonstrated the speed potential of LEDs by transmitting 140-Mb/s data 30 km and 560-Mb/s data 25 km.1,2 In these experiments the LEDs typically were modulated at large currents, 60-150 mA, and held at room temperature. In contrast to these devices, a unique edge emitting LED has been developed that has characteristics particularly attractive for use in loop transmission equipment.3 This low operating current LED (LOG-LED) couples 5-7 μW of peak optical power into a single-mode pigtail at the substantially reduced modulating current of 20-25 mA. It is attractive for reasons of reliability and cost to operate the LOC-LED at these low currents without temperature or power stabilization. The system experiments and analysis reported here confirm that the LOC-LED offers a reliable, low-cost, and easy to use alternative to diode lasers for the telephone loop plant.
© 1987 Optical Society of AmericaPDF Article