Scintillations of RGB laser beams in weak temperature and salinity-induced oceanic turbulence

Fluctuations in the optical signal intensity, known as scintillations, can severely degrade the performance of underwater wireless optical communication (UWOC) links. Using measurements data, this paper focuses on the variations of scintillations of red, green and blue (RGB) laser beams propagating in various weak turbulent water channels. The results show shorter wavelengths experience higher scintillation under the same turbulence. Moreover, the scintillation index decreases when the channel turbulence is dominated by temperature fluctuation. Furthermore, bit-error-rate (BER), which is a critical communication performance evaluation criterion, is also measured for the green laser under such turbulences. It is found that the turbulent UWOC link can still be retrievable in terms of BER performance when the turbulence is below a certain threshold. A steep increasing in BER occurs after the threshold.