Erbium Doped Fibre Amplifier Training System

ets 200 The Benchmark ETS is an EDFA (Erbium Doped Fibre Amplifier) Training System. Erbium Doped Fibre Amplifier (EDFA) is an optical amplifier that amplifies optical signals sufficiently enough to cover several tens of kilometers without any need for conventional repeaters. Moreover, as it works in the same optical domain, it avoids the need for several stages of signal conversion with their associated problems. Consequently, EDFA
finds extensive use in the fibre backbone.

edfa 01 440

The Benchmark ETS – EDFA Training System – addresses the need for a training setup that shows the building blocks of a typical EDFA as well as the characteristics of such blocks. All the blocks are given with proper input and output connections such that they can be configured in different modes of operation, such as co-directional and counter-directional operations. This modular approach also facilitates study of individual block characteristics wherever possible.


List of Items


Erbium Doped Fiber (spliced) - 3 different lengths
Erbium Doped Fiber (un spliced) - 1 no
Pump Laser 980nm, 100mW - 2 nos
Optical isolator – 1550nm - 1 no
Wavelength selective coupler (WDM), 980nm/1550nm - 1 no
Tap coupler - 980nm, 99:1 - 1 no
Single mode Patch cords - 8 nos
FOSM -U1000e 1550nm DFB LD unit - 1 no
Fiber Bragg grating - 1 no
Optical Circulator - 1 no
Optical Attenuator 1550nm, 980nm, 1550nm (Var) - 1 no
O/E Converter for  EDFA - 1 no
FOPM-102-01 Fibre Optic Power Meter - 1 no

Optional - Module 001

FOSM-D600 LD Driver - 1 no
FOTX-610 LD Modulator - 1 no
FORX-500 Optical Receiver - 1 no

Experiment Topics
Experiment Topics

Understanding the operating principles of EDFA

  • Working of EDFA in Co-Directional, Counter-Directional Pumping
  • Gain
  • Power Conversion Efficiency
  • Quantum Conversion Efficiency
  • ASE-ASE noise, Signal-ASE Beat Noise

Understanding the EDFA Building blocks

  • Wavelength Selective couplers – 980nm/1550nm
  • Tap coupler for 980nm – 99:1
  • Optical Isolators – 1550nm
  • Optical Circulators
  • Fibre Bragg Grating (FBG)
  • Optical attenuator – 1550nm

Characteristics study of EDF

  • Measurement of Absorption Co-efficient
  • Mode field diameter mismatch in EDF

Characteristics study of Pump Laser 980nm

  • I-P Curve
  • Knee Current

Characteristics study of Signal DFB Laser 1550nm (Module 001 required)

  • I-P Curve
  • Knee Current
  • Spectrum [Optical Spectrum Analyser (OSA) also required]

Factors contributing to EDFA Gain – Pump Laser power, length of Erbium Doped Fibre (Module 001 required)

  • Large and small I/P signal Vs Gain
  • Pump laser power Vs Gain
  • EDF length Vs Gain
  • Pump saturation
  • Signal saturation

Setting up a Fibre Optic link with EDFA

  • 1550nm, 34Mbps Data rate (Module 001 required)
  • Setting up a digital link (using the Benchmark OFT)
Fibre Ring laser (OSA required)
Noise Figure measurement (OSA required)



Pump Laser


Output power

Output power – adjustable

DFB Signal Laser


Output power



C-Band single mode fibre Max data rate    

Peak absorption near 1530nm

Peak absorption near 980nm

Second mode cutoff

Optical Isolator

Operating wavelength


Insertion loss

Wavelength selective coupler (WDM)

Operating wavelength


Insertion loss

Optical Circulator

Number of ports

Operating wavelength


Insertion loss

Fibre Bragg Grating





160mW (typ)

1µW to 100mW



1mW (typ)



2 Mbits/sec (NRZ)

6.0 ±1dB/m

≥ 3.0dB/m

920nm ±50nm



≥ 3.0dB/m

920nm ±50nm



19dB (typ)

1dB (typ)




35dB (typ)

1dB (typ)



90% – 95% (typ)

 *Specifications subject to change without notice

Ordering information

 Ordering information

  • ETS – EDFA training system
  • Module 001