Optically amplified passive optical networks: a power budget analysis

Passive optical networks (PONs) are being aggressively pursued as a means of delivering access network solutions. The cost benefits resulting from a reduction in the number of interfaces between nodes has enabled increasing deployment of a PON delivering fiber to the home and fiber to the curb. However, in many cases, the need for high split ratios or an extended-reach requires amplification to overcome additional losses. Erbium-doped amplifiers have a limited use in PONs since the operational wavelengths typically include backhaul at 1.3 mu m. Semiconductor optical amplifiers (SOAs) offer a cost-effective solution with a migration path toward integration; deployment options include its use as a preamplifier, booster, or midspan amplifier. We present a theoretical treatment that analyzes the amplified system operational requirements and justifies this analysis through the experiment. The analysis considers for the first time to our knowledge the dc offset that is introduced into the receiver as a result of the significant amplified spontaneous emission powers present in amplified PONs, where filter widths are typically 20 nm or greater.