As we face increasingly complex societal challenges, from climate emergencies to food shortages to health disparities, it is technology – particularly AI – that offers hope. However, society’s increasing integration with AI also brings massive, unprecedented demands for energy. To build a future where we can tackle the world’s most pressing problems and utilize AI responsibly and sustainably, we must look beyond conventional computing for technologies capable of delivering greater performance while using significantly less power.

The answer is quantum computing and photonics. Quantum computing has the potential to perform calculations at incredible speeds, which means it will solve problems instantly that would take 100,000 years for a traditional supercomputer. It will make it possible to tackle challenges that have long been considered impossible because it operates in new and different ways, surpassing the computational limits of conventional computers.

Quantum computing is expected to start delivering tangible real-world benefits around 2030 – addressing societal challenges, enabling the potential of AI, and advancing the progress of humanity by enabling developments such as personalized medicine, renewable energy and secure food supplies. And the latest development, photonics-based optical quantum computing, is now in the works. It brings with it the potential to enable all of this with even greater scalability, more accuracy and better energy efficiency – at the speed of light.

Why quantum computing is so challenging

Even after 35 years in development, quantum computing still faces major hurdles.

For one thing, it doesn’t scale easily or efficiently. Quantum bits, known as qubits, are the basic building blocks of information in a quantum computer. As the number of qubits increases, the physical size of a quantum computer grows, and more cooling systems are needed, which requires significantly more energy.

A second big challenge is error correction: as computations become more complex, “quantum noise” accumulates, making it difficult to perform accurate calculations. This noise may be in the form of disturbances from such things as electromagnetic radiation, temperature fluctuations or imperfect control signals, all of which can affect a qubit’s state.

The difference-maker to address these challenges is adding photonics – or optical technology – to the equation. Known as optical quantum computing, this technology is in development now – and will change the world as we know it.

How optical technology will advance quantum computing

Optical quantum computing will be based on photonics. Simply put, that means it will rely on light particles to transmit information. This is a vast leap forward from the electronics-based technology used today; electrons require energy to transmit and process data and they create heat, which then requires even more energy for cooling. Photons travel at the speed of light, need very little energy and generate virtually no heat.

Electron-based quantum computers face energy challenges because as their performance improves, their power consumption rises. They also need to be cooled to near absolute zero, so they can only operate with large-scale refrigeration systems that consume significant amounts of energy.

Optical quantum computing, on the other hand, will be able to operate at room temperature and atmospheric pressure, with no need for specialized cooling or vacuum systems – and therefore far less power consumption.

How quantum computing works

Whether it’s optical-based or not, the fundamentals of quantum computing are the same. Imagine a maze. Solving a problem on a classic computer is like navigating the maze by checking one path at a time. You follow a corridor until you reach a dead end, then backtrack to the last junction and try the next path. You continue this approach until you finally find an exit. As the maze becomes more complex, the number of paths you must check expands significantly.

Quantum computing is like exploring all paths in the maze at the same time, leaving only the path that leads to the exit. Because it can examine multiple possibilities simultaneously, quantum computing can solve far more complex problems than conventional computers. It does this through qubits, which are essentially the quantum equivalent of standard computer bits.

It will take between 1 million and 100 million qubits to be able to use quantum computers broadly for applications with major societal impact. We’re a long way off from achieving 100 million qubits, but we are working quickly and collaboratively to develop computers that will be able to handle 1 million qubits – a goal we aim to reach by the end of this decade.

Optical quantum computers help to advance this through multiplexing, which essentially means combining separate streams of data or signals and sending them simultaneously down a single fibre-optic cable. This expands the number of qubits much more quickly, getting us to the target of 1 million qubits – or even 100 million – sooner.

Why quantum computing matters for humanity

There are real-world problems that we can’t overcome today due to the limitations of conventional computers. Quantum computers are expected to make it possible to solve these kinds of problems. Optical quantum computers will advance this even further by enabling large-scale simulations and optimizations using less power.

Here is a look at what quantum computing can offer:

Quantum technology also has the potential to transform industries. For instance, in manufacturing it can optimize supply chains and carbon‑neutral product design, thereby supporting the move to sustainable industrial structures. In the information and communications technology industry, quantum computing can optimize global-scale communication networks, making them resilient to disasters and failures at a level conventional computers cannot handle. And, in the energy sector, innovations in power generation, energy storage and smart grid optimization arising from quantum technology are expected to drive progress toward decarbonization.

A photon pathway to the future

Optical quantum technology can provide a foundation for a sustainable future for humanity. It can help us to solve food problems by efficiently synthesizing fertilizers, optimize traffic and logistics in large cities, design optimal drug molecular structures tailored to each person, and design fusion reactors, which are expected to become new energy sources.

While conventional computers can produce approximate solutions for challenges like these, their accuracy is limited. Quantum computing can solve highly complex problems with significantly greater accuracy, and optical quantum computers will bring even greater advantages: high-speed processing with less power consumption. With optical technology’s ability to rapidly expand qubit capacity, we expect to achieve a fault-tolerant 1 million-qubit system around 2030. And that will change the world.

Optical quantum computing will take us much closer to solving some of our biggest global challenges, enabling responsible, sustainable AI and driving long-term societal benefits in business, health, science and more. It’s a technology that offers hope in ways that were once unimaginable.