The optical system achieves terabit-per-second capacity and integrates quantum cryptography for long-term security.

The artificial intelligence (AI) boom has created unprecedented demand for data traffic. But the infrastructure needed to support it faces increasing challenges. AI data centers will have to deliver faster, more reliable communications than ever before, while also facing increased power consumption and the threat of quantum security, which could one day break today’s encryption methods.

To address these challenges, a recent study published in Advanced Photonics Proposes a quantum-safe architecture that includes minimal digital signal processing (DSP) consumption and meets all the stringent requirements for AI-dation data center optical interconnect (AI-DCI) scenarios. This system enables data to move at speeds up to 100 per second with low power consumption, defending against future quantum threats.

“Our work paves the way for the next generation of innovative, scalable, and cost-effective optical interconnects that protect AI-powered data centers from quantum security threats while meeting the high demands of modern data-driven applications,” the researchers said in their paper.

The system is built around two primary goals: transferring data efficiently and ensuring long-term security and reliability. To facilitate data transmission, it uses a technique called self-homogen coherent (SHC) transmission, where the transmitter sends a reference signal along with the data. This makes it easier for the receiver to decode and process the signal while still maintaining high sensitivity and stability. The approach allows data to be sent at 1.6 terabits per second while keeping power consumption and costs low.

For security, the system integrates quantum key distribution (QKD), which generates secret encryption keys using the principles of quantum mechanics. These keys cannot be intercepted or copied without an address, allowing classical transmissions to be secured with AES-256 encryption augmented by quantum-generated keys. This also ensures strong, long-term security against future quantum computers.

To handle both classical (data) and quantum (QKD) signals, the system uses multimode fibers, which have several separate channels in the same section. This design allows different types of signals to travel side by side without interference, while being fully compatible with today’s fiber optic infrastructure.

In laboratory tests using seven-core fiber, classical data was transmitted with an SHC system, while quantum signals were stored with QKD. The system achieved an average encryption key rate of 229 kilobits per second and supported encrypted data transmission at 400 gigabits per second on each fiber core.

In a 24-hour continuous test over a distance of 3.5 km, simulating real-world conditions, the network ran at a total of 2 terabits per second of classical data while maintaining an average SCR of 205 kbps. This generates about 58,583 secure encryption keys every second. During the trial, the system consumed 1,440 session keys and successfully encrypted and decrypted 21.6 petabits of classical data in real time without any errors.

This new data transmission architecture not only meets the speed requirements of next-generation data centers, but also ensures strong security by combining photonics with quantum cryptography. It overcomes the constraints of existing systems and operates with very low transmission losses, making it both efficient and reliable.

“By combining state-of-the-art photonics with quantum cryptography, we pave the way for secure, energy-efficient and high-capacity networks capable of sustaining the economical growth of data-driven technologies,” the researchers noted.

The results suggest a promising direction for the development of more efficient and secure data transmission systems to handle the increasing demands of AI applications such as autonomous vehicles and large language models.