Copper-coated single-mode optical fibers

High strength metal-coated silica fibers

Copper-coated single mode fibers are high strength optical fibers that can be used for both high-temperature and cryogenic applications. Thin additional carbon underlayer is typically added to improve hermetic property of the coating and therefore provide improved mechanical strength. This fiber type is used in sensor systems for biomedicine, oil and gas industry, aircraft applications, high vacuum devices, etc.

Please see frequently asked questions below.



  • Higher mechanical strength with respect to polymer coated fibers.
  • Solderable coating allows feeding the fibers into high vacuum systems and provides no outgassing.
  • The temperature range is from -196C to +600C.



Copper coated single-mode optical fiber ОК-6/125-C/Cu ОК-9/125-C/Cu
Core diameter,  µm 6.8 ± 0.5 9.1 ± 0.5
Mode field diameter (Gauss),  µm 7.5 ± 0.6 10.0 ± 0.6
Clad diameter, µm 125 ± 1 125 ± 1
Coating diameter, µm 160 ± 5 160 ± 5
Fiber type Single mode Single mode
Coating material Copper / Copper alloy Copper / Copper alloy
Additional inner layer Carbon Carbon
Cladding offset, % < 2 < 2
Coating offset, % < 5 < 5
Attenuation at 1550 nm1, dB/km < 7 < 7
Wavelength range, nm 1500 ÷ 1600 1500 ÷ 1600
Core material silica Ge-doped silica Ge-doped
Clad material silica silica
Cutoff wavelength, nm < 1450 < 1450
Numerical Aperture (NA) 0.16 ± 0.02 0.13 ± 0.02
Δ n 0.009 ± 0.001 0.005 ± 0.001
Short-term bending radius, mm > 10 > 10
Long-term bending radius, mm > 25 > 25
Proof test, kpsi 100 100
Min operating temperature2,3, C -196 -196
Max operating temperature (short time < 60s)2, C 600 600
Max operating temperature (long time > 60s)2, C  < 400 < 400
Permissible rate of temperature change in the temperature range, C/min 5 5

1- under normal climatic conditions

2- in inert environment

3- at the minimum operating temperature, the integrity of the optical fiber is guaranteed



What is the loss value in Copper coated fibers?

Metallic coated fibers have higher losses than standard telecommunication fibers because when radiation passes through the fiber, small currents arise on the metal surface. That said, we have relatively low-loss single-mode fibers that are comparable to standard single-mode fibers. 

How Copper coating is removed? 

The metal coating from the fibers is removed by a chemical method. For example, immersing the fiber in a solution of ferric chloride followed by wiping with a lint-free cloth soaked in alcohol

Is it possible to metallize or recoat certain part of the fiber?

Yes, we can recoat the cleaned area. The length of the area with the recoated coating does not exceed 100 mm

What about splicing and termination Copper coated fibers?

Once the Copper coating has been removed, the fibers can be cleaved, spliced and terminated like standard telecommunications fiber. We manufacture patchcords with standard connectors

Are the fibers solderable?

Copper coated fibers can be brazed using a variety of solders using standard technologies

Do you offer heat-resistant cables?

Yes, we manufacture high temperature (up to 600 degrees) stainless steel braided cables. the maximum number of fibers in a cable is 24.