GEO50-H Geophysical Graded-Index Optical Fiber - Hydrogen Resistant, Carbon/Silicone/PEEK

Product Description

This optical fiber is designed for distributed temperature sensing and communications in applications where hydrogen diffusion is a concern, and in temperatures up to 160 ºC for long durations. The waveguide features a proprietary, hydrogen insensitive core structure to minimize the effects of hydrogen darkening, and also features a triple-layer coating system. The innermost layer is a thin carbon layer that effectively blocks hydrogen ingression to upper service temperatures. In addition, this carbon thin film reduces stressfatigue by ensuring that no water can attack the surface of the silica cladding. The secondary layer of silicone dampens attenuation-inducing compression and is easily strippable. The tertiary PEEK layer provides a high Young’s modulus outer layer with excellent chemical and abrasion resistance, low thermal expansion, and is a zero halogen material providing low smoke and toxicity. This combination is suitable for long-term use up to 160 ºC. In addition, this
fiber structure is ideal for low temperature and crogenic applications, operating indefinitely at low temperatures (~ up to 20 years, performance and reliability will vary depending on installation environment. Consult OFS for guidance).
Unit of Measure



N/A Multimode Graded-Index

Short-Term Bend Radius

N/A ≥ 4 mm

Long-Term Bend Radius

N/A ≥ 4 mm

Features and Benefits

Improved Waveguide Resists Hydrogen DarkeningMinimizes permanent losses due to hydrogen ingression in harsh conditions
Graded-Index 50/125 Fiber StructureCompatible with most commercially available Distributed Temperature Sensing (DTS) interrogators; can also be fusion spliced to similar hydrogen insensitive core optical fiber, and traditional lead-in optical fibers
Carbon/Silicone/PEEK Coating SystemFatigue resistant glass structure with low friction, crush and elongation resistant outer coating resists chemicals and abrasion and is easy to mechanically strip


N/A OFL @ 850 nm: ≥ 400 Mhz-km
OFL @ 1300 nm: ≥ 400 Mhz-km

Optical Properties

Operating Wavelength

N/A 850/1300 nm


N/A @ 850 nm: ≤ 4.0
@1300 nm: ≤ 2.0 dB/km

Numerical Aperture (Nominal)

N/A 0.20

Dimensions/Geometric Properties

Core Diameter (Nominal)

N/A 50 ± 3 µm

Clad Diameter

N/A 125 ± 1 µm

Clad Non-Circularity

N/A ≤ 2.0%

Core Non-Circularity

N/A ≤ 2.0 %

Coating/Buffer Descriptions

Coating Material

N/A Carbon/Silicone/PEEK

Operating Temperature

N/A -55 to +200 ºC

Mechanical and Testing Data

Proof Test Level

N/A 200 kpsi1.38 GPa