OKI and NTT Innovative Devices target FY2026 mass production for high-power terahertz devices using SiC and CFB integration

Japanese telecom equipment manufacturer OKI (Tokyo: 6703) and Kanagawa-based semiconductor firm NTT Innovative Devices have jointly announced the successful development of a mass production technology for high-power terahertz devices. The two companies plan to begin full-scale manufacturing in fiscal year 2026, positioning their breakthrough to address the rising global demand for 6G communication hardware and precision non-destructive sensing solutions. The platform utilizes crystal film bonding (CFB), a proprietary heterogeneous material integration technique from OKI, to bond indium phosphide (InP)-based uni-traveling carrier photodiodes (UTC-PDs) onto silicon carbide (SiC) wafers, resulting in significant yield gains and performance enhancements.

Originally used in printing system fabrication, OKI’s CFB technique has now been adapted to the needs of advanced photonic and semiconductor manufacturing. NTT Innovative Devices applied this approach to develop next-generation UTC photomixers that surpass existing limitations in thermal dissipation and signal output. Both companies cite this milestone as a key enabler for real-world deployment of terahertz-based hardware in wireless communication, security screening, and structural diagnostics.

How will high-power terahertz devices improve next-generation 6G communication performance and sensing precision?

Terahertz waves, occupying the spectrum between microwave and infrared, are increasingly viewed as foundational to ultra-fast, low-latency wireless networks. In addition to their utility in high-throughput communication, these electromagnetic waves enable high-resolution, non-invasive inspection of materials and structures—making them valuable in both telecom and industrial markets. Analysts expect terahertz components to form a critical layer in 6G deployment plans, where transmission capacity, latency, and energy efficiency must all be optimized in tandem.

Unlike X-rays, terahertz waves do not pose ionizing risks, allowing for safer deployment in civilian scanning systems and smart sensing platforms. However, their uptake has been limited by engineering constraints: low signal output at the component level and rapid atmospheric attenuation. To offset these challenges, high-output and thermally stable terahertz devices must be manufactured at scale, prompting collaborative innovation between electronics firms and academic consortia.

What technical advances allow OKI and NTT to increase output power and efficiency in terahertz photomixers?

NTT Innovative Devices, with support from multiple Japanese universities under the National Institute of Information and Communications Technology’s Beyond 5G program, focused on maximizing the output power of UTC-based photomixers—key devices that convert dual-laser optical input into terahertz frequency emissions. One of the central challenges in photomixer design lies in maintaining linear signal conversion under high light input. To overcome this, the teams directly bonded InP photodiodes onto SiC substrates, leveraging the latter’s superior heat dissipation to improve 1dB compression thresholds.

This design enhancement resulted in an output power exceeding 1 milliwatt in a single device—approximately a tenfold increase over conventional architectures. The structure also demonstrated improved linearity under high-frequency modulation schemes, such as multi-level QAM formats critical for 6G data encoding. The capability to sustain signal fidelity across long distances under load conditions makes the new design well-suited for both terrestrial and satellite communication platforms.

Why is crystal film bonding a game-changer in the scalable fabrication of terahertz components?

OKI’s crystal film bonding process addresses a longstanding yield and cost bottleneck in heterogeneously bonded devices. Traditional wafer-level bonding carries high defect risk due to minute inconsistencies over large surface areas. In contrast, CFB allows device-level InP crystal films to be lifted selectively and transferred precisely to matching SiC areas. This selective bonding reduces material waste—particularly critical as the active InP area is less than 10% of the total chip footprint—and improves bonding yields from approximately 50% to nearly 100%.

Furthermore, the approach aligns with broader industry efforts to improve sustainability in high-tech manufacturing. By enabling effective use of expensive compound semiconductors and minimizing discarded substrates, CFB technology reduces the carbon and materials footprint of terahertz device production. Institutional investors tracking ESG performance in advanced manufacturing are expected to view these gains positively, particularly in the context of scaling emerging technologies without incurring proportional resource costs.

How do analysts view the commercialization prospects of terahertz-based 6G infrastructure components?

While commercial 6G infrastructure remains several years from mainstream rollout, analysts agree that enabling hardware—particularly in the millimeter and terahertz frequency bands—will determine which vendors lead the next wave of telecom investment. As governments and telecom carriers prepare for spectrum allocation and pilot deployments in the latter half of the decade, suppliers able to guarantee component-level performance and manufacturing scale are expected to command early market share.

In this context, the collaboration between OKI and NTT Innovative Devices positions Japan as a strategic hub for terahertz innovation. By aligning R&D output with high-yield production readiness, the two companies are mitigating one of the key commercialization hurdles historically associated with terahertz systems. Institutional sentiment points to increased global demand for integrated components combining thermal reliability, high signal output, and minimal form factors—features demonstrably achieved in the announced prototypes.

What market-facing steps are OKI and NTT taking to promote terahertz solutions in FY2025–FY2026?

To attract global industry attention and strategic partnerships, NTT Innovative Devices will exhibit the newly developed terahertz device technology at Laser World of Photonics 2025 in Munich, Germany. The event, scheduled for June 24–27, is one of the world’s largest platforms for optical and photonic innovation and is expected to host numerous stakeholders from the semiconductor, telecom, aerospace, and healthcare sectors.

Ahead of FY2026 production launch, both OKI and NTT plan to expand engagement with global telecom equipment providers, component OEMs, and academic collaborators in Europe, North America, and East Asia. These steps are designed to ensure that the jointly developed platform becomes foundational not just in Japanese infrastructure projects but in international 6G and sensor integration roadmaps.

How will the terahertz platform contribute to Japan’s positioning in global 6G and sensing innovation?

Japan’s strategic focus on leading Beyond 5G technologies is reflected in this initiative’s blend of academic research, industrial engineering, and production efficiency. With research support from major universities—including the University of Tokyo and Kyushu University—the CFB-based terahertz platform is one of the most production-ready among emerging THz hardware solutions.

By bringing to market a solution that balances performance with manufacturing practicality, OKI and NTT Innovative Devices are expected to contribute meaningfully to both national and international communications infrastructure upgrades. Analysts also expect this platform to trigger derivative innovations in medical imaging, airport security screening, and industrial non-destructive testing—all markets where high-output, high-frequency sources can displace conventional X-ray and microwave-based solutions.

What are the forward-looking expectations for terahertz hardware markets beyond 2026?

With the global 6G market forecasted to grow exponentially through the 2030s, demand for foundational hardware such as photomixers, transceivers, and signal processing ICs is set to intensify. Market researchers anticipate early adopters will include national defense agencies, telecom equipment vendors, and semiconductor foundries experimenting with ultrafast integrated systems.

Given the strong yield gains and environmental efficiencies of OKI’s CFB approach, institutional investors are likely to watch for licensing opportunities, production scaling announcements, or supply partnerships across telecom, aerospace, and precision electronics verticals. Analysts expect follow-on developments may include miniaturized terahertz modules, chiplet-level integration, and co-packaged optics for ultrahigh-frequency systems.