Optical fiber connections Robust plug-in connector for optical fibers in harsh environments

Related Vendors

Rosenberger-OSI GmbH & Co. OHG

FAULHABER Drive Systems

Wuxi InfiMotion Technology Co., Ltd.

Until now, the use of optical fibers (LWL) in harsh environments has often been hampered by concerns about reliability and ease of handling. However, with the plug-in contact size 12, there is now a solution that ensures secure optical fiber connections even in industrial environments, aviation, or medicine.

In the protected environment of a data center or office complex, optical fibers are now standard. It is different, however, in harsher environments where dust, highly fluctuating and extreme temperatures, corrosive liquids and vapors, vibrations, and similar stresses occur. Furthermore, field use often demands a higher number of mating cycles, which is less than ideal for the use of optical fibers with their sensitive contacts.

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On the other hand, the rapidly growing demand for bandwidth does not stop at industries with harsh environments. The examples are obvious:

• Industry 4.0: Highly automated industrial production requires unlimited availability of data from various sources: from sensors and controllers to cameras for optical inspection, and up to edge servers with AI applications that process large amounts of data in real time.

• Aerospace: A large number of highly sensitive sensors and remote applications, as well as high-resolution optical applications and radar systems, generate vast amounts of data that need to be processed, stored, and transmitted. Additionally, there are extreme demands for reliability and low maintenance.

• Medical Technology: Image data from digital X-rays, magnetic resonance imaging (MRI), and computed tomography (CT), patient monitoring and data transfer between different buildings or to the attending physician, monitoring, and control of IT infrastructure in operating rooms—all of this requires enormous bandwidths. Furthermore, a hospital network is certainly one of the most critical infrastructures, demanding absolute reliability.

• Transportation: In traffic and railway technology, optical fibers are highly significant not only because of the bandwidth they achieve. The galvanic isolation achieved with fiber optics and the insensitivity to electromagnetic interference, which occurs with copper cables, also advocate for the use of optical fibers in this industry.

• Mining, Oil, and Gas Extraction: Both in underground resource extraction and in oil and gas production on platforms, highly complex technical systems are used, which are remotely controlled and meticulously monitored in real time using extensive sensors and numerous cameras. The high bandwidth demand is contrasted by extreme environmental conditions with dirt and dust, extreme temperatures, and vibrations.

• Broadcast: Immense amounts of data need to be processed not only in the studio but also when broadcasting live events. Television images in 4k and 8k resolution with complex sound, captured by numerous cameras and microphones, deliver a broad data stream. This must then be distributed to control room monitors, reporter booths, and acceptance points of broadcasting companies. Especially in events, numerous setups and changes are carried out, meaning an enormous number of mating cycles.

• Defense: Military defense and communication systems with optical and acoustic systems, as well as remote controls, also have a high bandwidth demand. The use involves the expectation of the most challenging environmental conditions, which place high demands on the reliability and robustness of network technology.

Connections for special requirements

The industry has responded to this need with the development of robust connection technologies. One example is Expanded Beam Optical technology. The EBO technology uses the simple principle of beam expansion to make fiber-optic connections less sensitive to contamination.

The light emerging at the end of the fiber is expanded into a parallel light beam with a significantly enlarged area through a lens optic (e.g., ball lens), then passes through the non-contact connection zone, and is bundled on the opposite side with an identical lens to the original diameter into the optical fiber.

Reduced effort for cleaning the contacts

Contaminants, such as a speck of dust or pollen that would block a significant portion or even the entire bundled beam, only obscure a small part of the light area in beam expansion, so correct signal transmission is not endangered. While standard optical fiber connectors need to be thoroughly cleaned before each installation, sometimes repeatedly depending on the level of contamination, to avoid performance losses, the effort required for cleaning contacts with EBO technology is significantly reduced—the disturbance from particles is minimized, as pollen or a speck of dirt only blocks a small part of the expanded light area. The light beam is thus no longer completely blocked, but only slightly weakened, maintaining full data transmission capability.

The EBO technology thus significantly contributes to the spread of optical fibers in harsh environments where dust-free operation or frequent maintenance of contacts is not possible or economically feasible.

For a flexible connector design

In addition to finished EBO connectors, there are now lens contacts that allow the integration of EBO technology into custom connector designs. They are designed for connection to multimode glass fibers and also use the principle of beam expansion to ensure reliable data transmission. Since the lenses do not come into direct contact, there is no mechanical wear, which increases the lifespan of the contact.

Reliably withstand up to 100,000 mating cycles

For use in challenging environments such as mining, aerospace, or the military industry, further requirements must be met. This particularly applies to the reliable retention of the connection, which must withstand vibrations or thermal and mechanical stresses over long periods. The number of mating cycles specified by the manufacturer is an established quality feature in this context. While connectors with a lifespan of 1,000 to 5,000 mating cycles are sufficient for simple and medium requirements, high-quality components achieve a much longer lifespan, meeting even extreme demands for connection security. For example, connectors utilizing Rosenberger OSI Size-12 lens contacts based on EBO technology and other high-quality components can reliably endure up to 100,000 mating cycles.

General and industry-specific standards

Of course, the components must also comply with the general standards and norms relevant for optical fibers, as well as the specific standards for individual industries. For example, the Size-12 lens contact is suitable for use in circular and rectangular connectors according to MIL-DTL-38999, a relevant standard for connectors in the aerospace industry.

Conclusion

The times when fiber optic cabling was economically feasible only in "suitable" environments are over. EBO technology (in singlemode and multimode) enables the use of suitable components even in harsh environments such as industrial settings, aerospace, or medical technology. In addition to high bandwidth, properties such as galvanic isolation and resistance to electromagnetic interference also make optical fibers advantageous, for example, in railway or military technology. With high-quality Size-12 EBO contacts that endure up to 100,000 mating cycles, connectors can be developed for all applications, meeting the demands for reliability and low maintenance.