Effects of downstream modulation formats on the performance of RSOA-based WDM PON

Abstract

We evaluate the effects of the downstream modulation formats (such as NRZ, inverse RZ, and Manchester) on the performance of the WDM PON implemented by using the reflective semiconductor optical amplifiers (RSOA's). The results show that, when we modulate the downstream signals in Manchester format, the performance of the upstream signal becomes insensitive to the operating condition of the RSOA.

All-optical format conversion from inverse-return-to-zero to non-return-to-zero using a Mach-Zehnder delay interferometer

“…The positive power penalty at the constructive port is caused by the extinction-ratio degradation. At the destructive port, as expected, the receiver has higher sensitivity for the NRZ format then for the inverse-RZ format, 8 which is due to the signal format conversion. 4 Conclusion 10-Gbit/ s all-optical format conversion from inverse-RZ to NRZ has been demonstrated.…”

“…The inverse-RZ format has received increasing interest as the downstream signal format to facilitate the upstream data remodulation in a wavelength-division multiplexing passive optical network ͑WDM PON͒. 7,8 The NRZ format, preferred in local networks, has the merits of lower bandwidth requirements, higher timing tolerance, and data-standard compatibility. The format conversion from inverse-RZ to NRZ can be used in connecting and interfacing optical network units ͑ONUs͒ and optical local area networks.…”