laboratory evaluation of wavelength laser changes in communication free space optical underwater (FSOUW)

Summary of the thesis In this research, the work examined the role that lasers play in unguided systems in underwater wireless systems (FSOUW), which determine the practical choice of laser system components in unguided systems, and examine the impact of the absorption of sea and ocean water to lasers and their association with laser wavelength. Three wavelengths (445, 532, 650) nm have been used to assess the validity of the selection of the appropriate water channel with 100 ml watts of laser as its transmitter energy. SNR, BER and SER were examined following five different water channels. These are pure tap water, and with salt, various concentrations of Malox (MG(OH)2 and Al (OH)3) and salt have been added in order to get high-turbid water, and the results show that mallox and salt content reduces the energy receiving the laser signal and causes disconnection. The charts on wavelength change were drawn with their absorption coefficient in the laboratory for several wavelengths and several types of ocean water and the results were discussed.