Performance evaluation of multi-wavelength visible light underwater optical communication

Abstract

A multi-wavelength underwater wireless optical communication (UWOC) was experimented and studied. The multi-wavelength 450 nm, 518 nm, and 655 nm laser source was used to transmit information in the underwater-air medium up to 17-meter. The data rate used in this study was up to 2.5 Gbps. The optical loss in the 450 nm, 518 nm, and 655 nm in water per meter were 0.55 dB, 0.56 dB, and 0.69 dB, respectively. Several environmental effects such as turbulence and temperature changes were investigated. The bit error rate (BER) value of red, green, and blue-laser can achieve up to $2.1\times {10}^{-5}$, $3.1\times {10}^{-8}$, $1.7\times {10}^{-12}$, respectively under turbulence influence. The laser beam is diverged due to wave and floating bubbles under turbulence influences, especially using a 655 nm red-laser diode. A temperature change did not significantly change the BER value as the turbulence did. The multi-wavelength 450 nm, 518 nm, and 655 nm laser source can achieve bit error rate (BER) under the forward error correction (FEC) limit. This study can further improve the researcher design of their UWOC system for various applications.