ABSTRACT
Phase-retrieval (PR) receivers can reconstruct complex-valued signals from two de-correlated intensity measurements, without the assistance of any optical carriers. However, both the calculation complexity with hundreds of iterations and the limited PR accuracy prevent it from being applied to high-speed photonic interconnections. Here we propose and demonstrate a PR receiver based on adaptive intensity transformation, with the capability of both fast convergence and high accuracy. Then we numerically reconstruct 56 GBaud QPSK signals after the 80 km standard single-mode fiber transmission by using our proposed PR receiver with only 50 iterations. In comparison with the recently reported PR receiver with the phase reset, our proposed PR receiver can reduce the required optical signal-to-noise ratio by 1.95 and 1.89 dB, in terms of 20% soft-decision and 7% hard-decision forward-error correction, respectively.
ABSTRACT
There are a large number of fouling organisms in the ocean, which easily attach to the surface of ships, oil platforms and breeding facilities, corrode the surface of equipment, accelerate the aging of equipment, affect the stability and safety of marine facilities and cause serious economic losses. Antifouling coating is an effective method to prevent marine biological fouling. Traditional organic tin and copper oxide coatings are toxic and will contaminate seawater and destroy marine ecology and have been banned or restricted. Environmentally friendly antifouling coatings have become a research hotspot. Among them, the use of natural biological products with antifouling activity as antifouling agents is an important research direction. In addition, some fouling release coatings without antifoulants, biomimetic coatings, photocatalytic coatings and other novel antifouling coatings have also developed rapidly. On the basis of revealing the mechanism of marine biofouling, this paper reviews the latest research strategies to develop environmentally friendly marine antifouling coatings. The composition, antifouling characteristics, antifouling mechanism and effects of various coatings were analyzed emphatically. Finally, the development prospects and future development directions of marine antifouling coatings are forecasted.
