Fiber Spools
Fiber Spools

Geophysical Fibers

Specialty fibers for distributed sensing in harsh environments

Downhole sensor, temperature, pressure, strain, flow, acoustic, vibration, hydrogen, Rayleigh, raman, brillouin, polyimide, carbon coat, silica, FIMT

Coherent’s geophysical fibers feature superior thermal chemical and hydrogen resistance for distributed temperature, pressure, flow, acoustic and strain sensing in harsh environments. Our pure silica core SM and graded index MM fibers provide the highest immunity to hydrogen induced losses. Coherent’s carbon coating provides high levels of hermeticity to germanium doped fibers for temperatures up to 200°C and superior mechanical reliability. Fibers are also available with mid-temperature acrylate (150°C), silicone (200°C) and polyimide (300°C) coating for industry leading temperature and chemical resistance.


  • Downhole sensing and Oil exploration - DTS, DSS, DAS
  • Pipeline monitoring - DTS, DAS
  • Smart City - Perimenter Sensing, Intrusion detection, traffic monitoring
  • Structural Monitoring - bridges, highways, railroad tracks

Features & Benefits

  • Pure silica core - Excellent immunity to the effects of hydrogen ingression
  • Hermetic Coating - Imperoved hydrogen resistance for germanium doped fibers
  • Long lengths proof-tested to 100kpsi

Optical Benefits

  • Minimal attenuation changes upon exposure to hydrogen and elevated temperature
  • Low intrinsic losses over critical wavelength ranges
  • High bandwidth graded index fibers for highly resolved distributed sensing
  • Excellent optical performance available with various coatings

Mechanical Benefits

  • Negligible degradation in strength after exposure to hydrogen
  • Hermetic Carbon coating enhances dynamic stress corrosion parameter
  • Maintains strength and reliability after exposure to rated maximum temperatures
    • 150°C with Mid-Temperature Acrylate coating
    • 300°C with Polyimide coating

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