For a long time, one of the main rules of progress in computing has been Moore’s law, which states that the number of transistors in an integrated circuit is doubled roughly every two years, thus allowing for an ever more powerful and efficient device. Nevertheless, as transistor sizes have been minimized, the industry is hitting physical and economic barriers. Electrons that move through very small silicon channels produce heat, leak, and are affected by quantum-mechanical phenomena at the smallest scales.
Due to that friction, a daring alternative has become possible: chips that use light instead of electrons. Such devices are known as photonic integrated circuits (PICs) or simply photonic chips. To communicate, photonic chips do not use electrons; instead, they use photons, the smallest units of light, to carry and process information.
In fact, it is a potential paradigm shift that is being talked about. When silicon-based transistors have problems because of density, heat and energy limitations, photonic chips pave the way to a high-speed, energy-efficient, and scalable computing future.
What are photonic chips, and how do they work
Photonic chips combine a variety of optical components on the same substrate. For example, these could be waveguides (channels for light), optical modulators (devices that encode information onto light), photodetectors (devices that convert light back to electrical signals if necessary), and optical amplifiers.
Whereas electrons flow through circuits in regular chips, photonic chips use light. As photons have the speed of light and do not cause resistive heating like electrons, photonic chips are said to have much lower energy loss and heat generation.
Most photonic chips currently use a hybrid method called Silicon photonics. This method utilizes the standard silicon-fabrication process while placing the optical components directly on the silicon wafers.
Why photonics solves the limits of transistor scaling
Transistor scaling is getting close to its physical limitations
Moore’s law was basically caused by one thing: engineers kept scaling down transistors, placing more of them on chips and increasing performance. This continued to work perfectly for many decades. Nevertheless transistor behaviors became really unstable when the geometry of transistors was reduced to only a few nanometers. Quantum tunnelling, leakage currents, and heat dissipation became very noticeable and as a result traditional silicon-based chips started to deliver less and less.
On top of that, the manufacturing of advanced chips has become very costly. Constructing state-of-the-art fabrication facilities (fabs) is a multi-billion dollar endeavor, thus completely changing the economics that previously made transistor scaling feasible.
Photonic chips avoid almost all of these issues
Photonic computing is not about gating silicon transistors and shrinking them. Instead, it uses light that doesn’t have quantum leakage or resistive heating in the same way. In that way, it is possible to avoid almost all of the heat and energy problems that go with downscaled transistors.
Since many optical components can be made on a silicon wafer using the current manufacturing tools (through silicon photonics), it is feasible to utilize the already existing supply chains and fab infrastructures.
Besides that, photonic chips have the potential to integrate plenty of features: computing, data transmission, interconnects, all on one single optical substrate. This fusion could bring back a version of Moore’s law, not only in the number of transistors but also in total system performance, bandwidth, and energy savings.
Early successes and recent breakthroughs
In a groundbreaking move, researchers at MIT unveiled a photonic processor that is not only fully integrated but also capable of executing a deep neural network purely on-chip by the use of light in December 2024. The chip performed the parts of the computation that are most challenging in less than 0.5 nanoseconds and to a level of classification accuracy that is comparable to that of standard electronic processors.
As per a recent comprehensive review of the year 2025, photonic chips have achieved a staggering energy efficiency improvement of up to 100 times and a computing density increase of up to 20 times in comparison with conventional electronics, which is largely due to the progress made in materials, fabrication, and design.
Photonic integrated circuits are beyond the realm of computing, where they are already implanted in data-centres, telecom networks, and high-performance computing (HPC). Optical interconnects have the ability to carry data at significantly higher bandwidths and lower latencies than are possible with traditional copper cables, thus they are seen as a solution to a rapidly growing bottleneck in large-scale systems.
Their use as the main component of an accelerator for AI and real-time data analytics, quantum computing, and high-throughput communications are just some of the few examples of the next generation applications that are emerging.
Challenges and what still stands in the way
Photonics chips, for example, could replace the transistors that are used in today’s electronics. They would not be as widespread as silicon electronics. Before that, photonic chips have to overcome many obstacles.
The first main issue is complexity. To build photonic circuits one has to have very tight control of light propagation, wavelength stability, and manufacturing of waveguides, modulators, detectors, and other optical components have to be very high precision. Due to this complexity, the integration with the existing electronics is very difficult.
There is also the challenge of hybrid dependence. A few photonic systems are only one component electronically controlled functions are used there specially where optical-electrical or electrical-optical conversions are involved. The conversion, in fact, is the bottleneck that limits the speed and the efficiency of photonic devices.
Besides that, some photonic chips demonstrate excellent results on a small scale in the lab. Still, it is difficult to scale them for mass production and widespread use. Cost, yield, and manufacturing standardization are some of the unresolved issues.
What this means for global industries: a transformative ripple effect
The promise of photonic chips extends well beyond raw compute performance. Here are some of the industries and domains likely to be transformed:
- Artificial Intelligence and Machine Learning: As AI models grow exponentially larger and more complex, they demand immense computational power. Photonic chips, with their speed, parallelism, and energy efficiency, could accelerate training and inference, enabling real-time analytics, faster model iteration, and lower energy costs.
- Data centers and cloud infrastructure: Data centers struggle with power consumption and heat generation. Photonic interconnects dramatically reduce energy usage and heat, enabling denser, more powerful server clusters without overheating.
- Telecommunications and networks: Fiber-optic communication has long used light. Photonic chips can bring that advantage to on-chip and between-chip communication, paving the way for ultra-fast, low-latency networks, critical for 5G/6G, real-time streaming, and global connectivity
- Quantum computing and secure communication: Integrated quantum photonics, combining photonic chips with quantum optical components, could accelerate the development of quantum computing and quantum-safe communication systems.
- Scientific computing and high-performance computing (HPC): Simulation, modelling, large-scale data processing in physics, climate science, genomics, all could benefit from chips that compute faster and more efficiently than traditional CPUs or GPUs.
Conclusion
Next-generation photonic chips represent a compelling answer to the limits facing traditional silicon transistors. They do not simply squeeze more transistors into a smaller space; they change the very medium of computation by replacing electrons with photons. That shift brings real advantages: speed, efficiency, scalability, and the potential to handle future workloads that traditional chips struggle with.
Yet the path to widespread adoption remains challenging. Manufacturing complexity, hybrid dependencies, cost and integration hurdles, all remain significant. It seems unlikely that photonic chips will replace silicon electronics overnight. Instead they are likely to emerge as a complementary tier, powerful accelerators for workloads where speed, bandwidth, energy efficiency, or scale matters most.
In essence, we are witnessing the beginning of a new era. Photonics may not entirely kill the transistor, but it will reshape how we compute. Industries across AI, cloud infrastructure, telecommunications, quantum computing, and scientific research stand to be transformed. If core technical and economic challenges are overcome, photonic chips could fulfil a promise Moore’s law can no longer deliver, ushering in decades of innovation powered by light.
