Expanded Beam Assemblies for Mil-Aero: What We Integrate, Test, and Document
Defense and aerospace programs often consider expanded beam optical interconnects when frequent mating, particulate contamination, and field serviceability are design concerns. The work that follows that choice—cable construction, furcation, sealing, environmental validation, and documentation—can become a significant source of schedule risk if it is not defined early. This post explains how Neptec approaches that work: the integration scope we own today, the thermal test capability we use for applicable validation programs, and the automation experience we bring to a potential production ramp.
Where we sit with expanded beam assemblies today
We work with third-party expanded beam connector systems, integrating supplied terminus assemblies into the cable build.
Our specialty is the assembly around the connector interface, including cable construction, routing, furcation, strain relief, environmental validation, and production documentation. This integration engineering and manufacturing expertise enables reliable, repeatable builds for long term programs.
The build envelope
Parameter | Capability |
Interconnect | Custom single-fiber and multi-fiber assemblies using physical-contact interfaces (for example, MPO/MTP or single-fiber APC where applicable) and expanded beam connector systems. |
Cable construction | Built to customer specification for their application environment. |
Fiber count | 1 to 240 and beyond. |
Branch count | 1 to n branches as required. |
Optical interface components | Customer-supplied or Neptec-sourced ferrules, termini, lens/expanded beam modules, and related connector components, subject to supplier and program requirements. |
Connector packaging and keying | Selected to the program interface requirement, including D38999, VITA 66-family, Series 79, or other customer-specified architectures where compatible with the selected optical interface. |
Thermal-test capability | −70°C to +180°C and up to 15°C/min chamber air ramp rate, subject to fixture loading, sample thermal mass, instrumentation, and the approved test procedure. |
Thermal testing to your program's profile
Thermal testing helps evaluate optical and mechanical performance across the temperatures, dwell periods, transition rates, and number of cycles defined by the program. Ours runs:
Temperature range: −70°C to +180 °C
Ramp rate: up to 15 °C/min
Purge: dry air at 3 to 5 cu. ft./hr, or nitrogen where the application calls for it
Where moisture control is required during sub-zero testing, dry-air or nitrogen purge can be used to reduce condensation and frost risk. The test plan should specify measurable atmosphere requirements, such as chamber dew point, relative humidity, oxygen concentration, or purge-flow setpoint, when those conditions matter to the intended use.
Send us your environmental requirements and we’ll run to it.
Automation: what it means for a production ramp
Neptec operates automated assembly lines for FA and MT assemblies, with the FA line runs at 200 pcs/hr and the MT line runs at 150 pcs/hr. These production lines demonstrate our ability to maintain process discipline and precision at scale, providing the manufacturing foundation needed for EBO production ramps. A full step by step walkthrough of the FA and MT automation process, including video, is available on our automation page.
Two things engineers should take from that:
Automation is especially valuable for repeatable, parameter-sensitive operations such as metered adhesive dispensing, controlled curing, fiber preparation, cleaving, alignment, and machine vision inspection. The applicable automated steps depend on the approved product process flow.
Final inspection and acceptance use a defined combination of automated measurement, machine vision, and trained operator review, selected for the product’s acceptance criteria and the capability of the inspection method.
We are evaluating how selected automation methods used in FA/MT production could be adapted to expanded beam assembly. Any future in-house EBO manufacturing scope will be communicated only after capability qualification and release. That's a roadmap rather than a shipping capability today, and it's grounded in lines that already run at rate.
How a program actually moves forward
Product Definition and Requirements (PRD) Interconnect, fiber type and count, branch geometry, environmental profile, and acceptance criteria captured before anything is built. Most schedule risk originates here.
Prototyping The first physical build, validated against the real installation.
Producibility assessment Can this be built consistently, at volume, with the tooling and process that will make it? This is where design details that drive yield get identified, while changing them is still cheap.
Acceptance Test Package (ATP) Defined by the selected interconnect and customer requirements. It may include pull test, optical insertion loss; return loss where applicable; fiber continuity and polarity; connector/terminus or lens-interface inspection; geometry or dimensional checks; and any required environmental screening.
As-built record Traceability for every shipped unit, including part numbers, lot data, measured results, and deviations. This record supports future reorders, often years after the original build and after the engineers who defined it have moved on. It also supports faster root cause analysis when an assembly fails on site or in application. With organized build records, engineers can quickly trace the history of a specific unit instead of reconstructing what was built from scratch.
Neptec’s quality management system is certified to AS9100D. Product acceptance remains based on the approved drawing, process documentation, inspection plan, and contractual test/acceptance requirements. A production unit is accepted based on its specified test and inspection results. A design or configuration is qualified only when it completes the customer- or program-approved qualification process, and the required evidence is accepted by the responsible authority.
Start with the requirement
If you have an expanded beam interface, an environmental profile, and a production target, we can tell you what we'd build, how we'd validate it, and where the producibility risks are.
