NTT and OptQC (Toshima-ku, Tokyo), a startup developing optical quantum computers, announced on the 3rd that they have signed a capital and business alliance agreement. The partnership aims to commercialize a fault-tolerant million-qubit-class optical quantum computer by fiscal 2030, strengthening end-to-end collaboration from research and development through commercialization and social implementation. NTT plans to invest in OptQC, though the investment amount has not been disclosed.

Optical quantum computers are a type of quantum computer that uses light as the carrier of information. While conventional computers process electrical signals through semiconductor processors, optical quantum computers perform calculations using physical properties of light such as photon number, polarization, and amplitude. By leveraging the principles of quantum mechanics, these systems are expected to rapidly solve problems such as quantum system simulations and integer factorization.

The biggest challenge for practical implementation is achieving FTQC (Fault-Tolerant Quantum Computing), which detects and corrects errors that occur during computation. Because even slight noise can corrupt quantum computation results, highly reliable quantum computing is essential.

The relationship between the two companies dates back to November 2025, when they signed a collaboration agreement to realize optical quantum computing and began studying million-qubit-class systems. Following that agreement, NTT established an optical quantum computing research and development hub at its Atsugi Research and Development Center (Atsugi, Kanagawa Prefecture). OptQC, meanwhile, began operating “MoQuren,” Japan’s first domestic optical quantum computer, this July at the Global Research Center for Quantum and AI Integration Technology (G-QuAT) at the National Institute of Advanced Industrial Science and Technology.

Under the new agreement, the two companies have also signed a joint research contract running through fiscal 2027. The collaboration will focus on scaling qubit counts using wavelength multiplexing technology, designing fault-tolerant optical quantum computers, and developing million-qubit-class system architectures, with the goal of completing designs for the required architecture and core component technologies.

The alliance combines NTT’s expertise in optical communications, networking, data centers, quantum information processing, and IOWN initiatives with OptQC’s optical quantum computing technology. The companies also plan to collaborate with user companies and research institutions in Japan and abroad to create use cases and drive social implementation.

Roadmap and Future Plans

Based on this alliance, the two companies have outlined a phased roadmap:

Fiscal YearInitiative2026Begin co-creation with user companies and research institutions2027Start supply chain development; develop 10,000-qubit-class system2028Begin PoC (proof-of-concept) trials using 10,000-qubit-class hardware2030Achieve fault-tolerant million-qubit-class optical quantum computer

From fiscal 2027, the companies will also collaborate on building the supply chain for the hardware. They will also leverage NTT’s customer network to encourage corporate partnerships.

Competitive Landscape in Quantum Computing

Quantum computer development is advancing globally across multiple technological approaches. The frontrunners include US-based IBM and Google, which pursue superconducting approaches, but these systems require cooling to near absolute zero (approximately minus 273 degrees Celsius). Optical approaches, by contrast, can operate at room temperature and are attracting attention for their scalability in increasing qubit counts.

OptQC is a University of Tokyo-born startup specializing in optical quantum computer development. The company has set plans to develop a 10,000-qubit-class quantum computer by fiscal 2027 and build a fault-tolerant million-qubit-class system by fiscal 2030.

With this alliance, NTT’s research capabilities and OptQC’s technology development strengths are expected to converge, accelerating efforts toward practical quantum computing. In particular, the fusion of NTT’s optical communications technology with OptQC’s optical quantum computing expertise could create synergies in scaling qubit counts and overall system design.

Quantum computers are expected to find applications across drug discovery, materials development, finance, logistics, and other fields, making the path to commercialization a closely watched development.