Viavi v. Platinum Optics: Why Patent Owners Need More Than Suspicion Before Filing

Patent litigation often begins before the patent owner can see every component inside an accused product. Supply chains are opaque, technical parts may have no visible manufacturer name, and some evidence is controlled by the accused company. But uncertainty does not turn discovery into a license to file first and identify a viable infringement theory later.

That is the central lesson of the Federal Circuit’s September 8, 2026 decision in Viavi Solutions Inc. v. Platinum Optics Technology Inc. The court affirmed an exceptional-case finding and an award of some attorney fees under 35 U.S.C. § 285. The decision is nonprecedential, so it does not create a new binding test. It is nevertheless a useful warning about two moments in a patent case: the investigation before filing and the obligation to reassess the case after contrary evidence arrives.

What Viavi believed was happening

Viavi owned four patents involving low-angle-shift optical filters used in three-dimensional sensing applications. Platinum Optics Technology, or PTOT, manufactured optical filters in Taiwan. The companies had previously litigated related foreign patents in China and Taiwan, and those disputes ended with agreements releasing PTOT from liability for certain past activity involving three filters.

Viavi later believed PTOT had begun supplying filters for a major company’s mobile devices sold in the United States. Viavi’s market share had declined, companies in the supply chain reportedly said PTOT had qualified as a supplier, and PTOT did not respond to a July 14, 2020 letter asking it to correct Viavi’s understanding.

What Viavi did not have was a device from the major company containing a PTOT filter. It possessed three filters from the earlier foreign litigation and had determined that one—called the 11246 Filter in the Federal Circuit opinion—met the major company’s technical requirements. Three weeks after sending the letter, Viavi sued in the Northern District of California.

The claim chart did not solve the factual problem

Viavi attached detailed claim charts mapping its patents to the 11246 Filter. That sounds like the sort of infringement analysis courts ordinarily expect before filing. The problem was the connection between that charted filter and the conduct alleged in the complaint.

The 11246 Filter in Viavi’s possession came from the earlier litigation and had been sold during a period covered by the parties’ release. Viavi did not have evidence that PTOT sold that filter after May 1, 2020, supplied it for the major company’s devices, or committed the alleged U.S.-directed acts involving that particular product. Viavi tried to cover the uncertainty by accusing the 11246 Filter “or a filter that is not materially different” from it.

The Federal Circuit agreed that the district court could find the investigation inadequate. A claim chart is important, but it must analyze accused subject matter tied to the infringement theory. Mapping claims to an older product does not necessarily establish a reasonable basis to accuse a different, unidentified product sold during a different period.

The Federal Circuit did not impose a universal reverse-engineering rule

The opinion should not be read to require a patent owner to buy, disassemble, and test an accused product in every case. The Federal Circuit expressly rejected such a blanket rule. Circumstantial evidence can support a reasonable pre-suit investigation, especially when the technology is difficult to obtain or inspect.

The court instead treated diligence as fact-dependent. Here, the relevant mobile devices were readily available for purchase. Viavi later bought several devices, took them apart, and found that the non-Viavi filter in one device was not the 11246 Filter. Viavi then brought a separate action directed to that newly identified component.

Those later actions mattered because they showed that the stronger investigation was feasible before the first suit. The court concluded that the district judge did not abuse his discretion by finding that Viavi came up short under these circumstances.

For patent owners, the practical rule is not “reverse engineer everything.” It is “use the best reasonably available evidence, and document why the investigation is reliable.” When the accused technology cannot be purchased or examined, the file should explain the obstacle and identify the technical, public, or circumstantial evidence supporting the infringement analysis.

Why the case became more dangerous after filing

The district court did not award fees for the entire case. It awarded some fees beginning when PTOT submitted a declaration stating that the 11246 Filter had not been manufactured or sold after May 1, 2020 and had not been supplied for the major company’s devices.

Viavi did not present evidence contradicting that declaration. It nevertheless kept the 11246 Filter in its infringement contentions and continued seeking broader discovery concerning filters that might be similar. The Federal Circuit held that the district court could reasonably view that conduct as prolonging a theory that had become untenable.

This distinction is important. A position may be weak when filed without being objectively baseless. But when credible evidence eliminates the factual premise, continuing to litigate the same theory can change the fee analysis. Patent contentions are supposed to shape discovery and trial preparation; they are not placeholders that preserve an unsupported product accusation while the plaintiff searches for another case.

Section 285 fees are different from bad-faith sanctions

35 U.S.C. § 285 permits a court to award reasonable attorney fees to the prevailing party in an “exceptional” patent case. Under the Supreme Court’s Octane Fitness framework, a case may stand out because of the weakness of a party’s position or the unreasonable manner in which it was litigated, considering the totality of the circumstances.

The district court denied PTOT’s request for sanctions under 28 U.S.C. § 1927 and its inherent authority because it did not find subjective bad faith or knowingly or recklessly frivolous conduct. That did not prevent a fee award under § 285. The standards serve different purposes and do not rise and fall together.

The Federal Circuit reviewed the exceptional-case determination for abuse of discretion and the underlying fact findings for clear error. That deferential review matters. The opinion confirms that district judges have room to assess the practical quality of an investigation and the way the parties responded as the record developed.

What a defensible pre-suit infringement file should establish

A useful pre-filing record begins with the patent claims, but it does not end there. Counsel and the technical team should identify the particular accused product or process, the version or model, the relevant time period, and the act that allegedly creates U.S. liability. The evidence should connect those facts rather than assume them.

The technical analysis should compare every asserted claim limitation to evidence about the accused subject matter. If a limitation cannot be observed directly, the file should identify the basis for an inference—such as documentation, testing, source code information, regulatory submissions, public specifications, or a technically sound explanation from a qualified person.

The legal team should also review licenses, releases, covenants not to sue, prior settlements, exhaustion issues, ownership, and marking history. In Viavi, the distinction between released pre-May 2020 conduct and alleged later conduct was central. A sound patent-licensing review should be completed before an older product becomes the reference point for a new infringement accusation.

Finally, the file should preserve what was reviewed, when it was reviewed, and why the available evidence supported the allegation. That record helps the client evaluate risk and can become important if the adequacy of the investigation is later challenged.

The investigation must continue after the complaint

Pre-suit diligence is not a one-time box to check. New evidence can strengthen a claim, narrow it, or eliminate it. A disciplined litigation team should create decision points after key declarations, source-code productions, product inspections, claim-construction rulings, and discovery responses.

When the evidence changes, the infringement contentions and case strategy should change promptly. That may mean withdrawing a product, narrowing claims, seeking a supported amendment under the applicable local rules, or ending the action. Keeping a disproven theory merely to obtain discovery into unidentified alternatives can increase exposure to fees.

This ongoing review also matters for accused infringers. A focused early response—supported by product records, sales information, technical evidence, or a declaration from someone with personal knowledge—may reveal whether the plaintiff has identified the wrong product or time period. The goal should be to define the real dispute, not simply generate cost.

What patent owners and accused infringers should take from Viavi

Viavi is not a rule that a patent owner must possess the accused product before filing, nor does it say that circumstantial evidence is insufficient. Its sharper lesson is that the infringement analysis must fit the product and conduct actually being accused. A technically detailed chart can still rest on an unsupported factual bridge.

The case also shows why patent litigation strategy must remain evidence-driven. Once the factual premise for a claim disappears, “belt and suspenders” is not a substitute for a viable theory. Discovery can develop evidence supporting a properly pleaded claim, but it is not meant to locate an entirely new basis for suing.

Tucker Law assists patent owners and businesses accused of infringement with patent-litigation strategy, technical claim analysis, licensing issues, and proceedings before the Patent Trial and Appeal Board. For help evaluating a potential patent case before positions harden, contact Tucker Law.

This article provides general legal information and is not legal advice. Pre-suit investigation duties, infringement contentions, and fee exposure depend on the facts, governing procedural rules, and jurisdiction.