Symmetric 100-Gb/s TWDM-PON in O-Band Based on 10G-Class Optical Devices Enabled by Dispersion-Supported Equalization

Increasing the serial bitrate to 25-Gb/s per channel as well as coexisting with the same optical distribution network of the 10G-ethernet passive optical network (EPON) is challenging. The bandwidth limitation and the reduced dispersion tolerance at high date rate make it much more difficult to achieve higher loss budget. In this paper, we have first shown a demonstration of a symmetric 4 × 25-Gb/s time-wavelength-division-multiplexed passive optical network system based on nonreturn-to-zero on-off-keying format supporting 0–20 km reach in O-band. 10G-class directly modulated lasers (DMLs) are employed to serve as both upstream and downstream transmitters owing to the low cost and the frequency chirp induced by DML can be used for bandwidth equalization. Instead of using digital signal processing, the chirp management and frequency equalization are simultaneously realized in optical domain through our proposed dispersion supported equalization technique. By employing a spool of dispersion-shifted fiber in optical line terminal (OLT), a single device can be used to simultaneously equalize the frequency response of multiple downstream and upstream channels. Then, we further use a semiconductor optical amplifier as a booster and preamplifier at the OLT for downstream and upstream, respectively. A power budget of 26 and 32 dB with 0–20 km reach of standard single mode fiber for downstream and upstream transmission at 1310 nm is obtained. The experimental results shown in this paper reveal that our proposed cost-effective scheme would be a promising candidate for the next generation 100G-EPON.