6-m/10-Gbps underwater wireless red-light laser transmission system

An underwater wireless red-light laser transmission system using 10-Gbps 16-quadrature amplitude modulation–orthogonal frequency-division multiplexing (OFDM) modulation based on a high-speed multimode 680-nm vertical-cavity surface-emitting laser (VCSEL) was proposed and demonstrated. This study is the first attempt to adopt red light for transmitting a 10-Gbps wireless signal 6-m underwater. With the adoption of the appropriate OFDM base bandwidth and modulation parameters after studying the frequency characteristics of the high speed multimode 680-nm VCSEL and contrast experiment of modulation parameters, a good bit error rate performance and clear constellation maps are achieved.