Gbit-Class Transmission Using SOA Data Rewriter for WDM-PON

We describe the transmission characteristics of a wavelength independent wavelength division multiplexing passive optical network (WDM-PON) based on a wavelength channel data rewriter (WCDR). The WCDR is composed of a linear amplifier (LA) and a saturated semiconductor optical amplifier (SOA), and by using the WCDR in optical network units (ONUs), we can erase the downstream signal and modulate the same wavelength channel with the upstream signal. In this paper, we analyze the data rewriting characteristic, the frequency chirp characteristic and the bit error rate (BER) degradation occasioned by the use of saturated SOAs. Furthermore, we report high-speed transmission with power penalty of less than 1 dB at bit rates of 1.25 Gbit/s, 2.5 Gbit/s and 10 Gbit/s for downstream signals and 1.25 Gbit/s for upstream signals after transmission through 40 km of single-mode fiber. key words: wavelength division multiplexing, passive optical network, semiconductor optical amplifier, gain saturation