Bit-rate transparent DPSK demodulation scheme based on injection locking FP-LD

We propose and demonstrate a bit-rate transparent differential phase shift-keying (DPSK) demodulation scheme based on injection locking multiple-quantum-well (MQW) strained InGaAsP FP-LD. By utilizing frequency deviation generated by phase modulation and unstable injection locking state with Fabry-Perot laser diode (FP-LD), DPSK to polarization shift-keying (PolSK) and PolSK to intensity modulation (IM) format conversions are realized. We analyze bit error rate (BER) performance of this demodulation scheme. Experimental results show that different longitude modes, bit rates and seeding power have influences on demodulation performance. We achieve error free DPSK signal demodulation under various bit rates of 10 Gbit/s, 5 Gbit/s, 2.5 Gbit/s and 1.25 Gbit/s with the same demodulation setting.