Quantum Computing Firm PsiQuantum Unveils Low-Loss Optical Switch Prototype for AI Data Centers

US-based quantum computing company PsiQuantum has announced that it has adapted its low-loss silicon photonics technology into an Optical Circuit Switch (OCS) designed for AI data centers. The device allows light signals to pass directly between fibers without the opto-electrical conversion required by traditional data center switches at every hop, thereby reducing power consumption and latency. As AI clusters grow, moving data between GPUs is becoming a significant bottleneck, making OCS a key technology for improving bandwidth and connection distance.

The company's 8x8 laboratory prototype achieved a typical insertion loss of 1.2 dB in tests, losing only about a quarter of the signal strength without the need for an amplifier. This figure is well below the 3 dB loss tolerance typical for data center optics. However, the prototype's port count remains small compared to competitors like Google's Palomar switch (136 ports) and Lumentum's products (300 ports). PsiQuantum stated that larger devices are in development, with a 64x64 version already taped out and a 72x72 version underway.

Unlike the microelectromechanical systems (MEMS) mirrors used by Google and Lumentum, PsiQuantum's switch uses circuits etched onto a silicon chip with no moving parts. This design aims to achieve lower loss and higher reliability through a solid-state silicon photonics platform. Although still in the prototype stage, the company argues that building these switches for conventional applications will de-risk the packaging, assembly, and supply chain for components used in its quantum computing business, viewing AI and quantum computing as complementary technologies.