Power-efficient multi-level modulation scheme for high-speed optical communications

In this paper, we propose a design for the transceiver of a new modulation scheme that is based on combining frequency and polarization modulated signals. This will be referred to as hybrid frequency-polarization shift keying (FPolSK) modulation. This modulation enables representing the signal points over multidimensional constellation points space, which ensures increasing the geometric distances between signal points, and in turn, improving the system power efficiency. To demonstrate the efficiency of our proposed technique, we derive an exact expression of the symbol error probability, and conduct a performance comparison between the proposed modulation technique and previously developed ones. Our results reveal that the proposed modulation scheme performs better than L-PolSK, L-DPSK, and L-FSK modulation schemes in terms of power efficiency.