OFSCN® Gold-Coated Fiber is widely used in extreme environments like aerospace, geothermal well exploration, and high-temperature industrial sensing due to its ultra-wide operating temperature range of -269°C to +700°C and exceptional hermetic sealing.
However, the metallic coating of gold-coated fiber presents unique challenges to traditional splicing and termination processes: How do you safely strip the hard metallic layer? How can splicing be performed while maintaining the fiber's original strength and hermeticity?
[Beijing Dacheng Yongsheng Technology Co., Ltd. (DCYS)] provides a complete solution for gold-coated fiber preparation and termination, ensuring you build stable and reliable optical links in the harshest environments.
I. The Challenge: Conflict Between Gold Coating and Traditional Methods
Traditional acrylate or polyimide coated fibers are typically stripped easily using mechanical or chemical methods. However, the coating on gold-coated fiber is metallic gold, which has the following characteristics:
- Extreme Hardness: Mechanical stripping can easily damage the fiber's silica glass surface, introducing new micro-cracks and thereby creating a risk of static fatigue.
- Chemical Inertness: Common stripping solvents cannot dissolve the gold coating.
- Hermeticity Maintenance: The core value of gold-coated fiber lies in its hermetic seal. Any process that damages the glass surface will compromise this critical barrier.
II. The Solution: Specialized Process for Gold-Coated Fiber
Handling gold-coated fiber requires special, high-precision processes.
1. Coating Removal: Electrochemical Stripping Method
For an inert metallic coating like gold, we recommend using an electrochemical or high-temperature ablation method for precise stripping; the electrochemical method is the most common and precise:
- Principle: Utilizing specialized electrochemical solutions and equipment, the gold coating is selectively dissolved or lifted off by precisely controlling the current and time, without touching or damaging the underlying silica (SiO2) glass cladding.
- Advantage: The stripping window is smooth and clean, maximizing the preservation of the fiber's original strength and surface integrity, and maintaining the glass's anti-fatigue properties.
2. Splicing: High-Precision Fusion Splicing
Since gold-coated fiber is used in high-reliability applications, the splice point is the most vulnerable part of the link. The highest precision splicing equipment must be used.
- Equipment Selection: Must use a fusion splicer with Profile Alignment System (PAS) functionality and precise arc control.
- Process Essentials: After splicing, geometrical misalignment of the fiber (e.g., axial offset, angle) must be minimized.
- Core Assurance: The splicer should feature a High-Strength Splicing Mode to ensure the splice joint has sufficient mechanical strength to withstand subsequent packaging stress.
III. Packaging and Termination: Building a 700°C-Rated Optical Link
After splicing, the exposed splice point and fiber ends require secondary protection and termination.
1. High-Temperature Connector
Standard plastic or epoxy-based connectors (such as FC, ST) cannot be used at 700°C. High-temperature connectors with all-metal or ceramic components must be employed.
- Typical Components: Utilizing ceramic ferrules and stainless steel housing, secured via specially designed high-temperature adhesives or mechanical clamping techniques.
- DCYS Solution: We offer custom high-temperature connectors matched to gold-coated fiber (e.g., rated for operating temperatures up to 450°C or higher), ensuring that the termination's optical and mechanical performance does not degrade due to heat.
2. Hermetic Secondary Protection
If the splice point is exposed to a corrosive or hydrogen-rich environment (e.g., downhole oil and gas), it must be protected with secondary hermetic packaging:
- High-Temperature Heat Shrink: For environments below 300°C, specialized high-temperature heat shrink tubing may be used.
- Fiber in Metal Tube (FIMT) Encapsulation: This is the highest level of protection. The splice point and fiber are placed inside a stainless steel or Inconel alloy metal capillary tube and laser-welded or brazed shut. This packaging offers the ultimate protection against pressure, temperature, and hermeticity challenges.
Conclusion: Reliability Stems from Professional Craftsmanship
Gold-coated fiber is the "Gold Standard" for overcoming temperature and hermeticity challenges, but its performance hinges on professional engineering treatment. From electrochemical stripping to high-precision fusion splicing, and finally to high-temperature metallic packaging, every process step is crucial.
[Beijing Dacheng Yongsheng Technology Co., Ltd. (DCYS)] not only provides high-quality gold-coated fiber but also offers a complete set of engineering guidance and customized high-temperature termination/packaging services to ensure your 700°C link is completely secure.
[Beijing Dacheng Yongsheng Technology Co., Ltd. (DCYS)]
Official Website: https://www.ofscn.org
Product Link: https://www.ofscn.org/optical-fibers/gold-coated.html
Technical Consultation: Please contact our specialized technical support team.