High-speed pulse-train generation using single-mode-fibre recirculating delay lines

A simple technique is described, whereby the delay properties of a series of two single-mode-fibre recirculating delay lines were used to generate a sequence of uniform, high-speed pulse trains. A single, short input was used to generate a sequence of 1.25 Gbit/s pulse trains that were uniform to better than ±0.3 dB.