At the core of this new communication paradigm lies a meticulously designed 5 × 5 array of vertical-cavity surface-emitting lasers (VCSELs). These semiconductor lasers operate in the infrared spectrum and are fabricated using standard lithographic techniques, enabling mass production at minimal cost. Each laser in the array can be independently modulated to transmit unique data streams. This parallelism effectively multiplies the communication capacity far beyond the capabilities of single-source systems, all within a footprint smaller than one millimeter. The compactness of this chip-scale laser array ensures it can be seamlessly embedded in a wide range of devices, from wireless access points down to smartphones.

Utilizing parallel data streams from multiple lasers is a critical leap in achieving high throughput. In practical tests, 21 out of the 25 lasers were activated and modulated using an advanced multiplexing approach, distributing information across numerous tightly packed frequency channels. This sophisticated modulation optimizes the use of the available bandwidth while adapting dynamically to channel conditions and noise. Each laser link individually achieved data rates between approximately 13 and 19 gigabits per second, culminating in an aggregate transmission speed exceeding 360 gigabits per second across the array—a record-setting figure for chip-scale optical wireless emitters coupled to free-space receivers.

The optical architecture designed to harness the laser array’s output embodies a feat of precision engineering. A custom microlens array collimates and directs each laser beam individually, followed by additional refractive elements that sculpt the ensemble of beams into a well-defined 5 × 5 grid of uniformly illuminated square spots at a receiving plane two meters away. This geometric structuring is critical to mitigating inter-beam interference, maintaining signal integrity, and ensuring distinct spatial channels for data transmission. Measurements confirm that the illumination uniformity exceeds 90 percent within the designated receiving region, effectively enabling multiple simultaneous users or devices to operate without deleterious cross-talk or data corruption.

This multi-beam configuration was validated in a multi-user demonstration scenario where four laser beams transmitted data concurrently. Each beam sustained robust communication performance, cumulatively delivering data rates around 22 gigabits per second. This achievement highlights the system’s potential to support dense user environments typical in offices, homes, and public venues—spaces where existing radio frequency bands are congested and susceptible to interference. The scenario vividly illustrates how spatially multiplexed optical wireless links, facilitated by carefully shaped and directed beams, can expand network capacity while preserving data fidelity.

Energy efficiency stands as a cornerstone of this innovation, addressing a growing global imperative to reduce power consumption in the face of escalating data traffic. While conventional Wi-Fi and cellular systems often exhibit substantial energy overhead per bit transmitted, the chip-scale optical wireless transmitter demonstrated an energy cost of approximately 1.4 nanojoules per bit. This figure is roughly half the energy consumption reported for state-of-the-art Wi-Fi systems operating under comparable conditions. Such reductions not only translate into lower operational costs but also diminish the environmental impact of burgeoning wireless infrastructure, aligning with sustainability goals.

The intrinsic physical properties of VCSELs contribute significantly to this enhanced energy profile. Unlike traditional radio transmitters, these semiconductor lasers emit light directly at high speeds, obviating the need for bulky and power-hungry amplification stages. Furthermore, the modulation techniques employed capitalize on the wide optical bandwidth, enabling data-rich signals to traverse free space without the spectral congestion typical of radio frequencies. This optical approach inherently circumvents interference from existing wireless networks, creating a complementary communication channel that relieves pressure on overcrowded spectrum allocations.

Deployment scenarios for this technology envision integration into standard indoor environments without substantial infrastructural overhaul. The small form factor of the laser array transmitter allows it to be embedded into ceiling fixtures, lighting modules, or dedicated access points, creating an overlay network that supplements traditional Wi-Fi or cellular services. Such optical wireless ‘hotspots’ could dynamically allocate bandwidth to devices based on spatial positioning, user demand, or application requirements, fostering seamless, high-speed connectivity throughout complex indoor spaces like offices, data centers, factories, and hospitals.

Despite these advances, the researchers acknowledge that further enhancements are possible, particularly in receiver design. The current experiments were constrained by the bandwidth of commercially available photodetectors, suggesting that integrating faster and more sensitive optical receivers could propel aggregate data rates even higher. This indicates a fertile avenue of future research, aiming to harmonize transmitter and receiver capabilities within an optimized optical wireless ecosystem.

Another significant consideration pertains to the robustness of optical links in real-world environments. Optical wireless communication inherently requires line-of-sight or minimally obstructed paths, raising challenges related to mobility, shadowing, and ambient light interference. The described system’s beam shaping and steering capabilities, however, offer a degree of adaptability, enabling spatial targeting and alignment that mitigate signal loss and maintain reliable operation amid typical indoor dynamics. Further development of adaptive optics and feedback control systems will enhance usability and resilience.

In summary, the pioneering chip-scale beam-shaped optical wireless system demonstrated by the Cambridge team represents a major stride toward next-generation high-capacity indoor wireless networks. By leveraging the compactness, efficiency, and parallelism of VCSEL arrays alongside bespoke optical beam shaping, the technology realizes extraordinarily high-speed data transmission with reduced energy consumption. It stands not as a replacement for radio-based communication but as a powerful complement, optimizing spectrum use and elevating user connectivity experiences in increasingly crowded digital environments.

This convergence of semiconductor photonics and precise optical engineering promises transformative impacts beyond traditional networking. Besides enhanced video streaming, virtual reality, and smart device integration, such systems could enable new applications in secure communications, augmented reality, and real-time sensor networks. Their scalability and integrability herald a future where ultra-fast, energy-conscious wireless connectivity is ubiquitously accessible within our everyday indoor spaces, redefining the digital fabric of modern life.

Subject of Research: Optical wireless communication, semiconductor lasers, VCSEL arrays, high-speed data transmission, energy-efficient wireless networks

Article Title: Chip-scale beam-shaped optical wireless system for high-speed and energy-efficient connectivity

News Publication Date: 11 March 2026

Web References:
https://www.spiedigitallibrary.org/journals/advanced-photonics-nexus/volume-5/issue-02/026018/Chip-scale-beam-shaped-optical-wireless-system-for-high-speed/10.1117/1.APN.5.2.026018.full

References:
H. Safi et al., “Chip-scale beam-shaped optical wireless system for high-speed and energy-efficient connectivity,” Advanced Photonics Nexus, 5(2), 026018 (2026). DOI: 10.1117/1.APN.5.2.026018

Image Credits: Image courtesy of H. Safi (University of Cambridge)

Keywords

Optical wireless communication, VCSEL array, beam shaping optics, high-speed data transmission, energy-efficient networking, indoor wireless systems, semiconductor lasers, free-space optical communication, multiuser optical links, infrared laser arrays

In a new paper published in Light: Science & Applications, a team of scientists, led by Professor Yidong Huang from the Department of Electronic Engineering in Tsinghua University and their collaborators from Peking University, Berxel Photonics Company Ltd. and Shenzhen Technology University have proposed the SUANPAN architecture for optical inner product instead of optical matrix operations. Just like the transistors in an integrated circuit, the independent basic computing unit in such scheme contains only one emitter-detector pair and could be scaled up to form a photonic computing chip. The elemental values of two vectors are encoded on the output intensity of the light-emitters and the photoresponsivity of the photodetectors (PDs) by a brand-new Bit Encoding and Analog Detecting method without requiring large-scale ADC or DAC arrays. The photocurrent of the PD would be proportional to the multiplication of the light intensity and photoresponsivity, and the final result of the inner product can be obtained by the summation of all the photocurrents. Since there is no interaction among the propagating light beams of all emitter-detector pairs and only the output currents of all PDs are connected, such scheme is scalable by increasing the number of emitter-detector pairs with no additional loss or error as well as flexibly reconfigurable and programmable for different computational tasks.

As a proof of principle, the SUANPAN architecture is implemented by utilizing an 8×8 vertical cavity surface emission laser (VCSEL) array and an 8×8 MoTe2 two-dimensional (2D) material PD array. In experiment, the calculation fidelity of random vector inner product can be as high as >98% for various bit precisions (2-bit, 4-bit and 8-bit), and >95% for various vector dimensionalities (@4-bit precision). Furthermore, such implementation has been successfully reconfigured to perform two typical AI tasks, Ising machine and artificial neural network (ANN). A randomly generated 1024-dimensional Ising problem is successfully solved, which is the highest dimensionality of optical Ising machine with heuristic algorithm. Meanwhile, a competitive classification accuracy of 88% is achieved for ANN on MNIST handwritten digit dataset. It is believed that photonic SUANPAN is capable to serve as a fundamental linear vector machine and is potential to enhance the computing power for future various AI applications.

These scientists summarize the operational principles and advantages of SUANPAN:

“It breaks through the traditional mindset of obtaining optical matrix transformations through interaction of light beams. Instead, there is no interaction among those propagating light beams of all emitter-detector pairs. Therefore, the SUANPAN can be decomposed into emitter-detector pairs as independent computing units. The scalability, reconfigurability and programmability of the SUANPAN architecture are only based on the multiplication, recombination and modulation of emitter-detector pairs without any additional cost. Compared with optical matrix transformations through interaction between light beams, the SUANPAN possesses following advantages: (1) With massive and industrial multiplication of emitter-detector pairs, the SUANPAN can theoretically be infinitely scalable. (2) The SUANPAN can be flexibly reconfigured and programmed to perform various specific computing tasks. (3) Only correcting the intensity of light beam is required, and there is no requirement to correct the phase term. (4) Even if one emitter-detector pair is broken during fabrication or operation, other emitter-detector pairs would not be affected, and only the operating dimensionality would be decreased.”

“SUANPAN provides a promising solution for optoelectronic analog-digital hybrid computing. Large-scale DAC and ADC arrays are usually required in optoelectronic computing. However, with Bit Encoding and Analog Detecting paradigm, M-bit digital electronic signal is converted to analog with in a set of M emitter-detector pairs, while each emitter-detector pair only represents 1-bit information. Thus, no DAC is required. At the same time, only one ADC is required to convert the total photocurrent into electronic digital signal. Therefore, the Bit Encoding and Analog Detecting computing paradigm greatly reduces the heavy burden introduced by ADC and DAC. Actually, it is also an important issue for the scalability of the SUANPAN architecture.”

                        Journal

                        Light Science & Applications

                        DOI

                        10.1038/s41377-025-02059-7 
                        Article Title

                        SUANPAN: scalable photonic linear vector machine
            Media Contact
                                WEI ZHAO
                Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, CAS
            zhaowei@lightpublishing.cn
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