Tower Semiconductor and Coherent Demonstrate 400Gbps/lane Data Transmission with a Silicon Modulator in a Production-Ready Sipho Process
Rhea-AI Summary
Tower Semiconductor (NASDAQ/TASE: TSEM) and Coherent (NYSE: COHR) demonstrated 400 Gbps/lane data transmission using a silicon Mach-Zehnder modulator built in a production-ready silicon photonics (SiPho) process on March 23, 2026.
The demo achieved a clear open eye at 420 Gb/s PAM4, used Coherent’s InP CW high-power laser, and targets next-generation 3.2T optical transceivers for pluggable and co-packaged optics in datacenter links.
Positive
- 400 Gbps/lane data transmission demonstrated
- 420 Gb/s PAM4 showed a clear open eye
- Production-ready SiPho process used for the silicon modulator
Negative
- Demo relied on Coherent’s InP CW high-power laser, not an all-silicon light source
- No commercial shipment timeline or binding customer agreements disclosed
News Market Reaction – TSEM
On the day this news was published, TSEM gained 5.19%, reflecting a notable positive market reaction. Argus tracked a peak move of +7.1% during that session. Our momentum scanner triggered 35 alerts that day, indicating elevated trading interest and price volatility. This price movement added approximately $1.01B to the company's valuation, bringing the market cap to $20.54B at that time.
Data tracked by StockTitan Argus on the day of publication.
Key Figures
Market Reality Check
Peers on Argus
TSEM fell 1.48% with several semiconductor peers also down (e.g., SITM -8.73%, LSCC -6.77%, SMTC -5.88%, MTSI -1.53%, QRVO -0.19%), indicating a broader sector pullback despite company-specific positive photonics news.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Mar 17 | AI power platform | Positive | -0.4% | Gen3 BCD LDMOS platform to address AI data-center power demands. |
| Mar 16 | AI networking deal | Positive | +11.1% | Collaboration with Oriole on nanosecond optical circuit switching for AI. |
| Mar 04 | OFC 2026 showcase | Positive | -1.6% | Plan to highlight SiPho roadmap and AI-oriented photonics solutions at OFC. |
| Feb 25 | Salience Labs partnership | Positive | -0.0% | Pre-production move for PIC-based optical circuit switches for AI data centers. |
| Feb 19 | Quantum photonics pact | Positive | -1.9% | Expanded collaboration with Xanadu to advance photonic quantum hardware. |
Recent AI and silicon photonics announcements have mostly been positive, yet 4 of 5 prior news events saw negative next-day moves, suggesting a tendency toward sell-the-news or profit-taking behavior.
This announcement continues Tower’s string of AI and silicon photonics developments, now adding a 400 Gbps/lane SiPho modulator with Coherent for 3.2T transceivers. Over the past months, Tower highlighted OFC 2026 participation, new SiPho-based AI networking collaborations with Oriole and Salience Labs, and a quantum photonics partnership with Xanadu. While these have positioned Tower at the center of AI data‑center optics, prior similar news often saw muted or negative price reactions, providing context for today’s trading.
Market Pulse Summary
The stock moved +5.2% in the session following this news. A strong positive reaction aligns with Tower’s broader push into AI-focused silicon photonics, highlighted by the 400 Gbps/lane SiPho modulator and prior OFC‑linked collaborations. Historically, however, several upbeat AI and photonics releases saw mixed follow‑through, with 4 of the last 5 news events followed by negative moves. Investors would need to watch whether enthusiasm fades as earlier gains do, or whether continued design wins and capacity investments sustain momentum.
Key Terms
silicon photonics technical
co-packaged optics technical
pam4 technical
AI-generated analysis. Not financial advice.
The demonstration uses a silicon MZM without use of exotic materials targeting next-generation 3.2T optical transceivers
MIGDAL HAEMEK, Israel, March 23, 2026 - Tower Semiconductor (NASDAQ/TASE: TSEM), the leading foundry for high-value analog semiconductor solutions and Coherent Corp. (NYSE: COHR), a global leader in photonics, today announced a breakthrough demonstration of 400 Gbps/lane data transmission using a silicon modulator built in a production-ready silicon photonics (SiPho) process. This achievement targets next-generation 3.2T optical transceivers and extends the capabilities of silicon for pluggable transceivers and Co-Packaged Optics (CPO) in datacenter connections.
Details of the modulator were presented last week at OFC. The demonstration showed a clear open eye at 420 Gb/s PAM4, and utilized Coherent’s InP CW high power laser. The performance milestone was enabled by the strong collaboration between Coherent’s advanced design expertise and Tower Semiconductor’s industry-leading SiPho platform.
The Optical transceiver market continues to outpace prior projections and next-generation bandwidth is required to continue the exponential growth in AI infrastructure.
“We strongly value the partnership with Coherent and are very excited about this breakthrough,” said Russell Ellwanger, CEO of Tower Semiconductor. “The result can extend the use of silicon for another generation of transceivers, re-utilizing the large multi-fab capacity investments we continue to make while we proceed with our work on more advanced material systems for next-generations”.
“We are pleased to partner with Tower Semiconductor on Silicon Photonics Platforms,” said Jim Anderson, CEO of Coherent. “Together with Tower Semiconductor, we are advancing high-performance optical interconnects for AI-driven data centers.”
For additional information about Tower Semiconductor’s SiPho technology platform, visit here.
About Tower Semiconductor
Tower Semiconductor Ltd. (NASDAQ/TASE: TSEM), the leading foundry of high-value analog semiconductor solutions, provides technology, development, and process platforms for its customers in growing markets such as consumer, industrial, automotive, mobile, infrastructure, medical and aerospace and defense. Tower Semiconductor focuses on creating a positive and sustainable impact on the world through long-term partnerships and its advanced and innovative analog technology offering, comprised of a broad range of customizable process platforms such as SiPho, SiGe, BiCMOS, mixed-signal/CMOS, RF CMOS, CMOS image sensor, non-imaging sensors, displays, integrated power management (BCD and 700V), and MEMS. Tower Semiconductor also provides world-class design enablement for a quick and accurate design cycle as well as process transfer services including development, transfer, and optimization, to IDMs and fabless companies. To provide multi-fab sourcing and extended capacity for its customers, Tower Semiconductor currently owns one operating facility in Israel (200mm), two in the U.S. (200mm), and two in Japan (200mm and 300mm) which it owns through its
About Coherent
Coherent is the global photonics leader. We harness photons to drive innovation. Industry leaders in the datacenter, communications, and industrial markets rely on Coherent’s world-leading technology to fuel their own innovation and growth.
Founded in 1971 and operating in more than 20 countries, Coherent brings the industry’s broadest, deepest technology stack; unmatched supply chain resilience; and global scale to help its customers solve their toughest technology challenges. Visit us at coherent.com.
Safe Harbor Regarding Forward-Looking Statements
This press release includes forward-looking statements, which are subject to risks and uncertainties. Actual results may vary from those projected or implied by such forward-looking statements. A complete discussion of risks and uncertainties that may affect the accuracy of forward-looking statements included in this press release or which may otherwise affect Tower’s business is included under the heading “Risk Factors” in Tower’s most recent filings on Forms 20-F, F-3, F-4 and 6-K, as were filed with the Securities and Exchange Commission (the “SEC”) and the Israel Securities Authority. Tower does not intend to update, and expressly disclaim any obligation to update, the information contained in this release.
Tower Semiconductor Company Contact: Orit Shahar | +972-74-7377440 | oritsha@towersemi.com
Tower Semiconductor Investor Relations Contact: Liat Avraham | +972-4-6506154 | liatavra@towersemi.com
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FAQ
What did Tower Semiconductor (TSEM) and Coherent announce on March 23, 2026 about 400 Gbps/lane?
Does the 400 Gbps/lane demo from TSEM indicate production availability for 3.2T transceivers?
What role did Coherent play in the March 23, 2026 silicon photonics demonstration with TSEM?
How does the TSEM/Coherent 400 Gbps/lane result affect silicon photonics for datacenter optics?
Was exotic material required in TSEM and Coherent’s 400 Gbps/lane silicon modulator demonstration?
