天下杂志报道上诠进入台积电COUPE矽光子FAU供应链，但未披露新增订单或财务增量

FOCI's Stock Surged 30-Fold in Five Years
How Did an Optical-Fiber Veteran Break Into TSMC's COUPE Silicon Photonics Supply Chain?
Source：Kuan Hsieh
Before light can enter a chip, it has to pass through the FAU. FOCI Fiber Optic Communications (FOCI) has transformed from a traditional passive fiber-optic component maker into a key supplier for co-packaged optics (CPO). Chairman Lin Sung-fu spoke with CommonWealth Magazine about engineering against thermal expansion at nanometer-level precision.
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How Did an Optical-Fiber Veteran Break Into TSMC's COUPE Silicon Photonics Supply Chain?
By Janet KangCommonWealth Magazine
FOCI Fiber Optic Communications, Inc. (FOCI; 上詮), Taiwan's stock has risen roughly 30-fold over the past five years, driven by a component few outside the industry have heard of: the fiber array unit, or FAU. The Hsinchu-based company, long known as a maker of traditional passive optical components, is now grouped alongside China's TFC (天孚), Corning, and optical communications leader Coherent as an FAU supplier — and viewed as a key piece of TSMC's co-packaged optics (CPO) supply chain. Foreign brokerage reports have listed FOCI as one of the market's primary FAU suppliers. Its stock crossed NT100twoyearsagoforthefirsttimeinmorethantwodecades,andbrieflytoppedNT1,000 mid-year.
The FAU is the final checkpoint light passes through before entering a chip, precisely aligning dozens of optical fibers to the waveguides etched onto a photonic chip. As AI servers drive surging demand for bandwidth and power efficiency, CPO is seen as a key technology for next-generation high-speed computing interconnects — and FAU yield and precision directly determine whether packaging houses can scale production.
Founder and Chairman Lin Sung-fu (林松福) reflected on three decades of industry ups and downs: "A lot of people pass through this field. But if you truly love it, you know the day will come."
From Fiber Couplers to FAUs
Lin's technical roots trace back to his time at the Industrial Technology Research Institute (ITRI), Taiwan's leading applied-research institute, where he continued the fiber-coupler research he had begun as an undergraduate physics student. A fiber coupler splits the signal from one optical fiber into multiple paths, or combines signals from multiple fibers into one — functioning much like an on-ramp or interchange on a highway. Imported couplers cost US10,000 a piece at the time; Lin domesticated the technology in eight months, a transfer that earned ITRI more than NT200 million and helped lay the foundation for Taiwan's optical communications industry.
A traditional-industry investor later recruited Lin to start a company, which settled in Hsinchu Science Park for its proximity to ITRI. In 2000, FOCI was acquired by a U.S.-listed company, only to be hit almost immediately by the dot-com crash as its parent's finances deteriorated. Worried the company would lose direction under American capital, Lin bought back 80% of its shares himself.
He was betting on a conviction that optical fiber — with its high bandwidth, long transmission range, and strands thinner than a human hair — represented an irreversible technology trend.
Chang Li-chiu (張立秋), currently a FOCI director who has twice served as its chairman and has known Lin for years, said what he admires most is Lin's persistence: staying in the fiber-optics field for so long "is genuinely difficult." Chang noted that Lin comes into the office nearly every day, still absorbed in R&D.
FOCI Chairman Lin Sung-fu began researching fiber couplers more than 30 years ago and has since expanded into the semiconductor industry. (Photo: Janet Kang)
Positioning Early for Integrated Photonics
FOCI's pivot toward semiconductor-grade components began well before the market started paying attention to CPO. Roughly a decade ago, Lin observed silicon-photonics chip company Luxtera partnering with TSMC to integrate chips with optical components — an early glimpse, he said, of what "integrated photonics" could become. (Luxtera was later acquired by Cisco.) Starting seven years ago, FOCI began systematically studying semiconductor industry technology and patent filings. "You need to understand where the global technology frontier is heading to stay ahead," Lin said. "Optical-communications knowledge alone isn't enough."
Five years ago, on the recommendation of the late Wu Kuo-ching (吳國精), founder of Taiwanese optical-communications company Browave (波若威), Lin recruited D.D. Hu (胡頂達), a TSMC veteran, as general manager, and began aggressively hiring semiconductor and packaging talent. Chang said FOCI's major push into CPO began only after Hu joined. Hu said that after ChatGPT set off the AI boom in 2021, the company accelerated its shift toward miniaturizing FAUs to semiconductor-grade precision; roughly half its R&D team now has a semiconductor background. Within Taichung's optics manufacturing cluster, Hu is widely regarded as a key figure in the CPO field; he has said at earnings calls that "packaging and FAU are closely linked."
The Limits of Thermal Expansion and Nanometer-Scale Precision
FAU performance directly affects packaging yield, and two bottlenecks stand out. The first is heat tolerance. Traditional telecom equipment is built for operating temperatures roughly between -40°C and 85°C, but advanced packaging processes routinely exceed 150°C. An FAU packs together metal, glass, adhesives, and plastic — materials with very different thermal expansion coefficients — and even slight deformation causes optical signal loss.
(Photo: Kuan Hsieh)
The second is alignment precision. A human hair is roughly 100 microns in diameter, but the alignment tolerance between fiber and chip must be held within 1 micron. Telecom applications historically required aligning a single, jacketed fiber; FAUs now require aligning 40, and in some cases more than 100, unprotected bare glass fibers simultaneously — with any single misalignment causing failure. Lin described it as "an impossible task." Through repeated testing, FOCI refined its processes and lifted yields, progressing from 40-fiber arrays to 80- and eventually 160-fiber arrays. The more fibers involved, the harder simultaneous alignment becomes — a barrier most competitors have struggled to clear.
One semiconductor analyst who closely tracks TSMC observed that the inflection point in FOCI's stock roughly coincided with when TSMC began developing COUPE (Compact Universal Photonic Engine), its silicon-photonics platform for CPO — a sign, the analyst said, that the market now treats FOCI as a leading indicator for the supply chain. The company weathered the dot-com crash in its early years; only as the market has come to recognize the commercial progress of silicon photonics has it drawn renewed investor attention.
From being acquired by a foreign parent and bought back, to pivoting into semiconductor-grade components, FOCI's trajectory reflects how Taiwan's optical communications industry is finding a new technological footing amid the AI wave. "The process has genuinely been difficult," Lin said, "but there's real satisfaction in the R&D — I'm excited every day." With Hu, the TSMC veteran, now leading the transformation alongside him, the pairing has become central to FOCI's push to secure a core position in CPO components.
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