Fast and reliable wireless connectivity is essential to everyday life. Video calling, streaming, virtual reality, and connected devices all rely on networks that are already heavily taxed. Currently, most wireless communications rely on radio-based technologies such as Wi-Fi and cellular networks. Although these systems have enabled global connectivity, they face increasing challenges such as congested radio frequencies, signal interference in crowded indoor environments, and increasing energy demands as more devices come online.
One new solution is optical wireless communication, which uses light instead of radio waves to transmit data. Light can significantly expand the available bandwidth, avoid interference with existing wireless systems, and be directed with high precision. These advantages make it especially attractive for indoor spaces such as offices, homes, hospitals, data centers, and public places where many users require high-speed connectivity at the same time.
In a study published in Advanced Photonics Nexusresearchers have developed a compact optical wireless transmitter that is extremely fast and energy efficient. The system is built around a small chip containing numerous semiconductor lasers, combined with an optical design that carefully controls the distribution of light. Combining these components creates a scalable platform for high-capacity indoor wireless communications.
Small laser array transmits large amounts of data
The core of the system is a custom-designed 5 × 5 array of vertical cavity surface-emitting lasers known as VCSELs. These infrared lasers are efficient and can operate very fast, making them commonly used in data centers and sensing technology. They can also be manufactured in large arrays using standard semiconductor manufacturing methods.
Each laser in the array can be controlled independently and send its own data stream. By running multiple lasers simultaneously, the system dramatically increases total data capacity compared to a single light source. The entire array fits on a sub-millimeter chip, making it suitable for compact wireless access points and potentially small enough to be integrated into devices such as smartphones.
The researchers manufactured the chip using established semiconductor technology and mounted it on a custom circuit board. Initial testing has shown consistent performance across the array with stable output and support for high-speed data transmission.
Record-breaking optical wireless speeds
To test the system, the team created a free-space optical link spanning two meters. Each laser transmitted data using a modulation scheme that splits the information into multiple closely spaced frequency channels. This approach maximizes bandwidth efficiency and adapts to changes in signal quality.
Of the 25 lasers, 21 were active during testing. Individual lasers reached data rates of approximately 13 to 19 gigabits per second. Combined, the system achieved a total data rate of 362.7 Gbit/s. This is one of the highest speeds reported for a chip-scale optical wireless transmitter combined with a free-space receiver.
The researchers noted that performance was limited by the bandwidth of the commercially available photodetectors used in their experiments. With more advanced receivers, the same system can reach even higher speeds.
Forming lights for multi-user connectivity
Using many light beams at once poses the important challenge of preventing overlaps that can cause interference. To solve this, the researchers designed an optical system that precisely shapes and directs each beam.
The microlens array first aligns and straightens the light from each laser. Additional lenses then organize the beam into a structured grid of square illumination areas on the receiving surface. This layout ensures that each beam covers a specific area with minimal overlap.
Test results showed that the light distribution achieved more than 90% uniformity across the illuminated area at a distance of 2 meters. This structured approach allows you to assign different beams to different users or devices within the same room.
The team also demonstrated multi-user functionality by activating multiple lasers simultaneously. In testing with four simultaneous beams, each connection remained stable, delivering a total data rate of approximately 22 Gbit/s. The results confirm that multiple optical links can operate simultaneously without significant interference.
Uses less energy than Wi-Fi
Improving energy efficiency is critical as the demand for wireless data continues to increase. Traditional radio-based systems require more power to support higher speeds, increasing both cost and environmental impact.
Optical wireless systems use laser light sources that are inherently energy efficient and capable of high speed operation without complex power requirements. As a result, it consumes significantly less energy per bit of transmitted data compared to traditional Wi-Fi systems. Measurements show that energy usage is around 1.4 nanojoules per bit, which is about half that of leading Wi-Fi technologies under similar conditions.
Complement your existing network
Researchers stress that optical wireless technology will not replace Wi-Fi or mobile phone networks. Instead, it works in parallel with them to handle large amounts of data traffic in indoor environments and reduce congestion in radio-based systems.
In the future, similar systems could be built into ceilings, light fixtures, or wireless access points to provide fast, secure, and energy-efficient connectivity to many users simultaneously. This approach provides a practical path to next-generation indoor wireless networks that combine compact laser arrays, high-speed transmission, and precise optical control to achieve better performance without increasing energy consumption.
