Insights

How polymer innovation is paving the way for fiber optic development

By Jason Fant, Global Fiber Optics Market Manager, Zeus

Fiber optic sensors are central to a whole host of applications, from identifying leaks in nuclear power plants to guiding surgical procedures. While the technology has evolved to detect and relay complex data, optical fibers cannot withstand harsh environments and physical hazards. When deployed in such conditions, optical fibers must be protected or modified if they are to survive and perform optimally. Failure to do so could compromise long-term reliability and may even risk the integrity of your entire project. 

Increasingly, design engineers are turning towards polymer coatings to provide the kind of multi-environment fiber optic protection needed to maximize the performance of sensors and networks in all kinds of applications. Individual optical fibers can be coated with an additional polymer layer over their primary cladding, while fiber bundles can be contained within a tube or sheath, either as a fiber optic cable or as a sensor. In addition to containment, this polymer-based tubing provides physical protection from environmental threats. 

Research and development efforts constantly increase the scope and efficacy of polymer-based protective coatings and sheathingsLast yearfor instance, Zeus collaborated with Luna Innovations to assess the potential of a new optimized PEEK coating process developed by Zeus specifically for fiber optic applications. 

The results were exciting. Joint research revealed that the coating was thermally stable once applied and not susceptible to shrinkage, even during large temperature swings. The new optimized PEEK coating was also proven to deliver improved resistance to chemicals and radiation, as well as exceeding the performance of uncoated fibers under several other conditions. 

Protecting fiber optics
Of course, there is no ‘one size fits all’ protective polymer solution.  An understanding of the characteristics of the polymers available and the types of protection offered by various coatings and sheathings is imperative for correct specification.  

To support engineers as they investigate bestmatch protection for their applicationZeus devised the table below outlining the different benefits and potential uses of the six principal polymers deployed in fiber optic coatings and sheathings: ETFE, FEP, PEEK, PFA, PTFE, and PVDF 

While not an exhaustive list, it provides a starting point to guide research into which polymers may provide the critical protection required for your specific fiber optic innovation. 

Polymer Key Benefits Common Applications Industry
ETFE
  • Working temperature:
    -308 °F to 302 °F
    (-189 °C to 150 °C)
  • Temperature stability
  • Good radiation resistance
  • Mechanical integrity
  • Low coefficient of friction
  • Low water absorption
  • Improved strength
  • Sterilizable by multiple methods
Easily removed coating for crimp and cleave assemblies in environments with broad temperature fluctuations

Aerospace

Medical

Nuclear

Telecom fiber

FEP
  • Working temperature:
    -328 °F to 400 °F
    (-200 °C to 205 °C)
  • Temperature stability
  • Chemical resistance
  • Low water absorption
  • Low coefficient of friction
  • Good tensile strength

High transmittance housing for fiber optic lighting

Low-friction lead-in tubes.

Aerospace

Automotive

Medical

Telecom fiber

PEEK
  • Temperature maximum:
    to 572 °F (300 °C)*
  • Radiation resistance
  • Thermal stability
  • Chemical resistance
  • Abrasion resistance
  • Mechanical integrity
  • Tensile strength
  • Enhanced pushability
  • Sterilizable by multiple methods

Strain and temperature sensing in harsh environments

Embedded sensors for structural and composite monitoring

Aerospace

Automotive

Energy

Medical

Nuclear

PFA
  • Working temperature:
    -328 °F to 500 °F
    (-200 °C to 260 °C)
  • Temperature stability
  • Chemical resistance
  • Low coefficient of friction
  • Tensile strength
  • Low smoke, toxicity

Protective housing for aerospace data cables

Pipeline

Monitoring

Aerospace

Energy

PTFE
  • Working temperature:
    -328 °F to 500 °F
    (-200 °C to 260 °C)
  • Low coefficient of friction
  • Low water absorption
  • Chemical resistance

Low friction liner for fan-out kits and cables

Cryogenic cables

Temperature sensor delivery

Aerospace

Automotive

Medical

Telecom fiber

PVDF
  • Working temperature:
    -58 °F to 302 °F
    (-50 °C to 150 °C)
  • Temperature stability
  • Chemical resistance
  • Radiation resistance
  • Mechanical integrity
  • Low coefficient of friction
  • Low water absorption
  • Tensile strength

Cables requiring low flame spread, limited smoke generation

Housing for high radiation environments up to 1000 MRad

Medical

Nuclear

Telecom fiber

* Note that the maximum temperature for PEEK coatings ensures it is acceptable for applications that do not require dielectric or insulating properties.

Engineering custom polymer solutions
When it comes to fiber optic technologies, market needs are constantly changing. In response, work is always in progress to develop stronger, more versatile protective polymer solutions that will pave the way for innovative new fiber optic technologies.

That’s why, at Zeus, we have increasingly found ourselves working with customers to develop and test custom polymer coatings and sheathings that achieve the specific protection requirements of unique fiber optics products or applications.

In truth, I believe it comes down to this: the more R&D teams and product design engineers seek to explore the possibilities of polymer protection, the more expansive fiber optic applications will become, and the faster their development cycles can be implemented.

Author: Jason Fant, Global Fiber Optics Market Manager, Zeus

Jason is recognized within the industry and amongst peers, as a specialist on polymer protection for fiber optics. He is regularly called upon by R&D teams and innovation centers worldwide to apply his expertise in polymer solutions to aid the development of new fiber optic powered processes, products and applications.