Experimental Demonstration of Improved Equalization Algorithm for IM/DD Fast OFDM

We experimentally investigate the fast orthogonal frequency division multiplexing (OFDM) scheme with improved performance in compensating asymmetric channel impulse response using single-tap equalizers. We demonstrate for the first time 18 Gb/s intensity modulation and direct detection optical fast OFDM over both 80 km standard single-mode fiber at $1.55~ \mu \text{m}$ and 1.15 km hollow-core photonic bandgap fiber at $2~\mu \text{m}$ . The results show that the proposed algorithm has better performance and lower complexity than the previous schemes under asymmetric channel impulse responses. In addition, the results validate that the emerging 2 $\mu \text{m}$ fiber-optic system can achieve the performance close to that of the 1.55 $\mu \text{m}$ system.