Quantum dot semiconductor optical amplifiers at 1.3 µm for applications in all-optical communication networks

Single- and multi-channel amplifications using a quantum dot (QD) semiconductor optical amplifier (SOA) for data signals up to 80 Gb s−1 are investigated. A reach extension of 30 km for 40 Gb s−1 NRZ OOK data signals resulting in a total transmission distance of 75 km is presented. 80 Gb s−1 RZ OOK single-channel amplification demonstrates pattern-effect-free operation up to 6 dBm input power and 6 dB gain compression. Additional 40 Gb s−1 NRZ OOK interfering channels induce low crosstalk up to −6 dBm channel input powers (OSNR penalty below −3 dB at a BER of 10−9) proving the suitability for multi-channel booster amplification. Wavelength conversion via four-wave mixing is found to be feasible with less than 1 dB received power penalty at a BER of 10−9 for downconversion and is limited only by the achievable OSNR for upconversion. Using cross-gain modulation open eye diagrams are demonstrated for 80 Gb s−1 RZ OOK wavelength conversion. Therefore, QD SOAs demonstrate their suitability for a variety of applications in future all-optical ultra-high-speed networks toward 100 Gb s−1