Reach extension of passive optical networks using semiconductor optical amplifiers

Passive optical networks are being aggressively pursued as a means of delivering access network solutions. The cost benefits resulting from reducing the number of interfaces between nodes has enabled increasing deployment of passive optical network delivering fibre to the home and fibre to the kerb. However, in many cases, the need for high split ratios or extended reach requires some form of amplification to overcome the additional losses. Erbium doped amplifiers are not appropriate for passive optical networks since the operational wavelength typically include backhaul at 1.3 mum. Semiconductor based amplifiers offer a cost effective solution with a migration path towards integration. Implementation options include using the SOA as a pre-amplifier, booster or mid-span amplifier. This paper summarises the potential for SOAs from both a theoretical and practical perspective.