Development of Underwater Optical Wireless Communication Systems

In recent years, the exploration of ocean has attracted a lot of attention all over the world. During ocean activities, such as ocean construction, event detection/tracking, ocean research, underwater tour and so on, the use of an adequate communication tool to transmit and receive real-time information is crucial. Compared with sonar communication, optical transmission technology is considered as better approach for underwater communications due to its promising features like high data rate, network security, immunity to electromagnetic interference, and compact units, etc. To reinforce the capability of underwater research, in this project, several issues concerning on epitaxial growth, device design/manufacturing, packaging and signal modulation will be conducted to find the best way for the realization of underwater optical wireless communications. The following is the project objects: (a)Epitaxial growth of high-speed (f3dB ＞ 100 MHz) InGaN LEDs with optimized quantum well number by MOCVD. (b)According to the current spreading length, we can determine the maximum device size of the emitting pixels that is useful to improve device performance (Po ＞ 400 mW & Vf ＜ 3.5 V @ 350 mA) of TO-packaged LED arrays with parallel and series-connected pixel geometry. (c)LED array-based luminaires with a protection case made from high thermal conductivity, and corrosion/oxidation resistant materials will be realized.(d)With LED arrays as optical transmitters, 200 Mbit/s underwater optical wireless links with the receiver, optical lens, and intensity modulation scheme will be performed.(e)Different strategies such as modifying the modulation format (e.g., QAM), using the clock and data recovery circuit, or OFDM-based optical link will be proposed to improve system performance (data rate ＞ 400 Mbit/s).

Project ID:PB10708-2349
External Project ID:MOST107-2221-E182-046