Solar panels will soon enable underwater wireless connections

Researchers at Zhejiang University in China use solar cells to achieve fast wireless communication underwater. An approach that could enable devices that transmit data and produce power.

Although solar cells are designed to convert light into energy, researchers have shown that they can also be used to achieve high-data-rate wireless underwater optical communication. This new approach could offer a low-power, cost-effective way to transmit data underwater.

Solar panels will soon enable underwater wireless connections

Optimized for communication

Solar cells are designed to capture incoming scattered light from a fairly wide area. Its efficiency is far better at channeling that light into an electrical circuit than it is at converting it into a data signal. Compared to using radio or acoustic waves, light-based underwater wireless communication exhibits higher speed, lower latency, and requires less power. Now, however, a team from China’s Zhejiang University says it’s possible to tackle this.

Until now, achieving high-speed links using off-the-shelf silicon solar cells has required complex modulation schemes and algorithms, which are computationally resource-intensive that use additional power and create high processing latency,” said lead scientist Dr. Professor Jing Xu. “Using (computer) modeling and simulation of connected solar cells, we optimized the peripheral circuit, which significantly improved the performance of our solar cell-based detector,” he adds.

Need for efficient underwater communication

According to Jing Xu, there is a critical need for efficient underwater communication to meet the growing demand for underwater data exchange . Above all, for activities to protect the oceans around the world. For example, in coral conservation efforts, data links become necessary to transmit data to divers, manned submarines, underwater sensors, and unmanned autonomous underwater vehicles to surface ships that support this work.

In the journal Optics Letters , Xu and his team report on the lab experiment in which they used an array of commercially available solar cells to create a lensless system optimized for high-speed underwater optical sensing. Solar cells offer a much larger detection area than photodiodes traditionally used as detectors in wireless optical communication.

“To the best of our knowledge, we demonstrated the highest bandwidth ever achieved for a commercial optical communication system based on silicon solar panels with a large detection area ,” Xu said. “This type of system could even allow data exchange and power generation with a single device.”

Experimento de los investigadores de la Universidad de ZhejiangExperiment by researchers at Zhejiang University

underwater tests

The researchers tested the new design in which they used a 3×3 solar panel to create a 3.4×3.4 centimeter detection area, in a 7-meter-long water tank that emulated an underwater channel. Mirrors were also used to extend the length of the optical signal path, creating a transmission distance of 35 meters.

This system showed reliable stability, low power consumption, and high performance . Even though a simple detection scheme was used, this new system exhibited a much higher detection bandwidth, leading to a higher data rate, compared to other studies using commercial silicon solar cells with a large detection area as detectors.

In order to optimize this system for real-world application in underwater communications, Xu and the other researchers plan to study its performance with weak optical signals . These tests will demonstrate how the system performs in muddy and/or moving water. In turn, they are also working on making the system more practical by adjusting key parameters such as the number of solar cells in the array and the required reverse bias voltage.