GUEST BLOG: Solving harsh environment challenges in fiber applications

Blog

March 17, 2025

When designing components for aerospace and defense systems, engineers must design not only for performance but also for reliability as many military applications fall under extreme environmental conditions. These conditions challenge the reliability, durability, and operational efficiency of equipment, necessitating innovative engineering approaches – especially with fiber-optic interconnect solutions that must withstand high demands in the field.

Typically, harsh environments involve extreme temperature fluctuations, which pose a significant challenge to equipment performance. High temperatures can degrade insulating materials and accelerate wear, while low temperatures may cause embrittlement and reduced conductivity. Ensuring that materials and designs maintain structural integrity and functionality across wide temperature ranges is critical.

Mechanical vibrations and shocks are also common stresses for equipment in defense applications. These forces can lead to connector dislodgment, fatigue failures, and eventual malfunctions. Overcoming these issues requires mechanical stability through reinforced housings and advanced locking mechanisms. Optimized geometries can also distribute stress more effectively, thereby reducing fatigue.

Environmental contaminants such as dust, water, and corrosive chemicals can compromise performance by causing abrasion, short circuits, or corrosion. High ingress protection (IP) ratings and effective sealing techniques are vital to safeguarding components in such conditions, achievable by integrating multistage sealing systems. To withstand even the harshest of environments, encapsulation and conformal coatings are used to further enhance the durability of the connectors.

Fiber-optic connections, essential for high-speed data transmission, are particularly vulnerable to contamination, physical stress, and alignment issues. Maintaining optical clarity under extreme conditions is crucial for reliable communication. Similarly, applications that involve frequent connection and disconnection demand connectors capable of enduring numerous cycles without degradation. This durability requires the integration of advanced contact systems and wear-resistant materials.

Commonly used physical contact (PC) connections are known for their good attenuation values and are therefore widely used within high-end applications that rely on high-speed data transmission. To deliver the quality needed, contact ends must be aligned perfectly in a dust-free environment. Each mating cycle requires a cleaning procedure of all the contacts to ensure perfect mating conditions.

It’s also true that the direct physical connection between the polished fiber ends forces microscratches and continuing contact wear. The high susceptibility of the technology reduces the overall service life of the connectors to a few hundred mating cycles, maximum, and comes with high maintenance requirements.

Established expanded-beam technologies minimize the impact of contamination and alignment issues. With a longer service lifetime, the systems are less sensitive to contamination and mechanical influences. They don’t require cleaning before every mating cycle, but still need to be cleaned on a regular basis.

Regular cleaning comes at a price, however: Insertion loss and return loss characteristics of these expanded-beam solutions are far worse than comparable PC solutions. It seems like engineers have to choose: Good data-transmission performance combined with high maintenance effort, or mediocre data-transmission performance combined with medium maintenance effort. This dilemma often means that engineers avoid fiber as much as possible.

An example of a fiber-optic interconnect solution that can mitigate these issues is the ODU Expanded Beam Performance technology. It has high transmission characteristics and can go beyond 50,000-plus mating cycles for consistent performance in harsh environments. The technology is resistant to mechanical stress, contamination, and environmental influences and can deliver stable optical performance with minimal insertion loss. The compact design also enables high-density systems that can connect multiple fibers at the same time.

Harsh environment applications demand engineering solutions that can meet and exceed the requirements in the field. By addressing challenges such as thermal stress, mechanical vibration, environmental contamination, and optical signal integrity, engineers can ensure that systems perform reliably under extreme conditions.

Thomas Mittermeier is Strategic Business Development Manager at ODU.

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