PsiQuantum samples optical switches for AI networks

PsiQuantum is sharing optical circuit switch samples with potential customers, adapting its silicon photonics technology from quantum computing to AI network infrastructure. The company reported lab results showing an insertion loss of 1.2 decibels, crosstalk performance of 40 dB, and reconfiguration in under three milliseconds. Its 8×8 demonstrator operates without optical amplification. Commercial products are expected in the coming months. The company did not name the customers receiving samples or announce any deployments.

The application targets connectivity between GPUs and other computing resources, where data movement can limit large AI cluster performance. Optical circuit switching creates direct light paths between ports, avoiding the optical-to-electrical conversions in traditional electronic switches. This approach could lower network power use and latency, allowing accelerators more time for computing.

The demonstration device has no moving parts or mirrors. PsiQuantum describes it as strictly non-blocking, enabling new connections without rearranging existing ones. Low insertion loss helps preserve optical power as signals travel through the network. The company is developing larger devices but has not published their specifications. The reported reconfiguration time refers to changing optical paths, not transit time for traffic.

The switch extends a photonics platform developed over nearly a decade for PsiQuantum’s planned fault-tolerant quantum computers into conventional computing. CEO Victor Peng stated this opportunity arose from solving the hardest scaling problems early in the company’s roadmap to utility-scale quantum computing. PsiQuantum uses a 64×64 barium titanate switch in its quantum systems but noted it is not required for the AI networking demonstrator or initial products, leaving it as a possible path to faster future devices.

Other suppliers are also developing optical switches for AI networks. Salience Labs recently raised $125 million and unveiled a 64-port switch. PsiQuantum’s 8×8 demonstrator is smaller, with larger devices in progress. Port count alone does not determine relative performance, which also depends on optical loss and reconfiguration speed.

PsiQuantum’s manufacturing work is supported by a $100 million U.S. Department of Commerce award under the CHIPS and Science Act, covering optical switches, photon detectors, and advanced packaging. This funding helps advance its technology for both quantum and classical computing applications.