03 / Component
What is an EML?
An electro-absorption modulated laser: a laser and a modulator built on the same chip, so that the device both makes the light and encodes data onto it.
(In simple terms: a laser that writes the data onto its own beam.)
Why it matters
Integrating the modulator with the laser removes a coupling step, which saves power and space — both scarce inside a transceiver. EMLs are the workhorse light source for high-speed data-centre links.
How it works
- A laser section generates a continuous beam.
- An adjacent absorber section is switched electrically.
- When the absorber is on it blocks the beam; when off it passes it.
- The result is a stream of light pulses carrying the data.
Inputs and outputs
- Made of
- An InP die carrying both the laser and the electro-absorption section.
- Takes in
- InP substrates and high-speed driver electronics.
- Produces
- A modulated optical signal ready for a fibre.
Where it gets stuck
Each speed generation demands a faster absorber without more power or heat. Fabrication tolerances tighten with every step, and yield falls with them.
A general statement about the technology. It is not a claim about any named project — where T2C can evidence a specific delay, it appears in the intelligence ledger with its source.
Where it sits in the chain
T2C tracks the delivery end of this chain. An upstream stage is shown as having happened — capacity cannot be billing unless the parts were made — and simultaneously as untracked, because no supplier, order or shipment record sits behind it.
Public companies in this area
These companies make the components this stage depends on. Except where a row states a named agreement or a disclosed order, no document links them to any operator, site or contract T2C tracks — making a component is not the same as having been awarded work, and this table never implies otherwise.
| Company | Role in the chain | What the evidence shows | Quote | Source |
|---|---|---|---|---|
| Lumentum Holdings NASDAQ: LITE EML | Component maker Produces indium-phosphide lasers, including electro-absorption modulated lasers for high-speed data-centre optics. | Makes the component Its own product page for a 200G PAM4 EML. Establishes that Lumentum makes EMLs. It names no customer — though AXT separately discloses supplying Lumentum, which is recorded on the substrate row above. No counterparty named in the document As of 16 Aug 2026 | Not connected No market-data provider is configured. T2C never prints a stored price. | Lumentum Holdings Inc. |
| Fabrinet NYSE: FN EML | Contract manufacturer Provides advanced optical packaging and precision manufacturing for optical components and modules designed by others. | Makes the component Its FY2025 results, which describe the business as advanced optical packaging and precision manufacturing services to OEMs. Establishes the business model; names no optical customer. No counterparty named in the document As of 27 Jun 2025 | Not connected No market-data provider is configured. T2C never prints a stored price. | Fabrinet |
Glossary
Every term that appears above, defined. Each opens in place.
-
A laser that encodes data onto its own beam.
EML
An electro-absorption modulated laser: a laser section and an electrically switched absorber built on one chip. Integrating them removes a coupling step and saves power and space.
-
The compound semiconductor optical lasers are grown on.
indium phosphide
A compound of indium and phosphorus. Unlike silicon it emits light efficiently, which makes it the base material for the lasers carrying data inside AI clusters.