Precision Optical Fiber Delay Line

Precision Optical Fiber Delay Lines are used in applications that demand setting exact delay of system. Delay Lines manufactured by Fibrain thanks to the use of master class connectors  guarantee to obtain repeatable connections with low insertion loss. Selected fibers together with an advanced winding process guarantee extremely low optical loss of the entire line. Additionally it is possible to make a delay line in an acoustic and vibration absorbing version. Fibrain Precision Optical Fiber Delay Lines are characterized by the market-leading latency tolerance of 0.005%. As a standard delay modules are placed in 19″ distribution boxes.


  • Delay of line customized to customer requirements
  • Use of master class optical connectors, optical fiber with low attenuation and precise winding technology guarantees low insertion loss of line
  • Extremely high delay accuracy
  • Available in an acoustic and vibration absorbing version


  • Laser spectroscopy
  • Test and measurement system
  • Quantum optics
  • Optoelectronic oscillators
  • Optical gyroscopes

Technical parameters

Optical fiber parameters 1

Fiber typeG.657A2 2
Attenuation @1310 nmdB/km≤0.35
Attenuation @1383 nmdB/km≤0.34
Attenuation @1490 nmdB/km≤0.23
Attenuation @1550 nmdB/km≤0.21
Attenuation @1625 nmdB/km≤0.23
Mode filed diameter (MFD) @1310 nmµm8.8 ± 0.4
Mode field diameter (MFD) @1550 nmµm9.8 ± 0.5

1. Full datasheet of optical fiber available on request

2. Other type of fiber Attenuation @1310 nmon request




Optical connectors parameters

Maximum insertion loss ILdB≤ 0.1
Minimum return loss RLdB≥ 65 (APC), ≥ 55 (UPC)
Concentricityµm≤ 0.3
Longitudinal angle of the ferrule hole≤ 0.2
Apex offsetµm≤ 30
Fiber heightnm-30 – +30
Radius of curvaturemm7-12 (APC), 10-20 (SC UPC), 7-25 (LC UPC)
Polishing angle8 ± 0.3 (APC), 0 ± 0.2 (UPC)

Measure at wavelength 1310, 1550 nm




Standard specifications 2*

Nominal length [km]Maximum insertion loss [dB] 3*Typical delay [µs]

Delay tolerance  0.005 %

2. Other lengths available on request

3. Insertion loss with optical connectors at 1550 nm wavelength