High-speed digital lightwave communication using LEDs and PIN photodiodes at 1.3 μm

At the wavelength of 1.3 μm, fiber loss and dispersion are sufficiently small that many lightwave communications applications can use simple and reliable LED transmitters and PIN photodiode receivers without avalanche gain. Bit rates can be as high as several hundred Mb/s. With new high-speed devices based on III–V semiconductors and microwave silicon IC technology, we have designed two fully retimed optical regenerators that operate at 1.3 μm and at bit rates of 44.7 and 274 Mb/s to study the potential of the LED-pin approach. A detailed analysis of the baseband characteristics of the LED, the fiber, and the receiver leads to an overall equalization approach that minimizes receiver noise. The success of this performance optimization is corroborated by bit-error measurements under simulated system conditions. The results suggest repeaterless operation over distances up to 24 km at 44.7 Mb/s and 8 km at 274 Mb/s for a cable loss of 1 dB/km and a bandwidth of 1000 MHz·km. The use of lasers in such multimode fiber sytems would permit larger margin allocations and penalties than those chosen for LED systems, but would not lead to substantially longer repeater spacings.