Kyushu Team Demos 180 Gbaud KNN Optical Modulator
Kyushu University and Sumitomo Chemical report a potassium sodium niobate modulator that operates at ultrafast speeds and outperforms thin-film lithium niobate on modulation efficiency.
Updated on Nov. 2, 2026 in Materials Science
Kyushu University and Sumitomo Chemical Co., Ltd. have demonstrated that potassium sodium niobate (KNN) can serve as a core material in optical modulators, with a device operating at 180 Gbaud. The research was accepted as a post-deadline paper at the 52nd European Conference on Optical Communications (ECOC 2026) in Spain.
Why it matters
Optical modulators are central to high-speed data transmission, and a material that offers higher modulation efficiency while fitting existing semiconductor processes could ease the path to commercial deployment. The results position KNN as a possible alternative to thin-film lithium niobate, the current reference material in this field.
The KNN modulator achieved a VπL value below 0.7 Vcm, almost three times the modulation efficiency of TFLN, and operated at 180 Gbaud in a laboratory demonstration. The source does not quantify the expected cost savings over TFLN wafers, and practical deployment timelines remain unannounced.
The players
Kyushu University
A leading national university in Japan whose researchers designed, fabricated, and evaluated the KNN optical modulator.
Sumitomo Chemical Co., Ltd.
A Japanese chemical manufacturer that produced the KNN thin-film wafers and has mass-production capability built through its work on piezoelectric MEMS.
European Conference on Optical Communications (ECOC)
One of Europe's largest international conferences on optical communication technologies, where the research was presented.
The details
Sumitomo Chemical produced KNN thin-film wafers, which can be formed by sputtering and are highly compatible with existing semiconductor manufacturing. Kyushu University designed, fabricated, and evaluated the optical modulator, and the companies say they hope to accelerate work toward practical use.
Timeline
Research results were accepted as a post-deadline paper at ECOC 2026, held in Málaga, Spain.
The article announcing the research was published on November 2, 2026.
The Big Picture
The KNN demonstration positions potassium sodium niobate as a challenger to thin-film lithium niobate, which has been the reference material for high-speed optical modulators. If the efficiency gain and cost projection hold at scale, the result could shift which material platform the optical communications industry builds on next.
Higher-efficiency modulators could eventually support faster data transmission in networks that carry internet and telecom traffic. The source indicates the work is aimed at practical use, but no product availability date has been given.
The takeaway
Materials that reduce the energy and voltage needed to switch light signals can raise the ceiling on network speed without rebuilding the whole supply chain. Watch whether the cost advantage over TFLN is confirmed once production scales beyond the laboratory.
Further reading
For more on the materials driving this work, see Materials Science coverage.
