PRODUCTS - FIBRE OPTICS - ERBIUM DOPED FIBRE AMPLIFIER

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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.


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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.

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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/li>
  • Mode field diameter mismatch in EDF
Characteristics study of Pump Laser 980nm
  • I-P Curve/li>
  • Knee Current
Characteristics study of Signal DFB Laser 1550nm (Module 001 required)
  • I-P Curve/li>
  • 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/li>
  • 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)
Specifications
Pump Laser
Wavelength
980nm
Output power
160mW (typ)
Output power - adjustable
1µW to 100mW
DFB Signal Laser
Wavelength
1550nm
Output power
1mW (typ)
SMSR
>30dB
EDF
C-Band single mode fibre
Max data rate
2 Mbits/sec (NRZ)
Peak absorption near 1530nm
>6.0±1dB/m
Peak absorption near 980nm
≥ 3.0dB/m
Second mode cutoff
920nm±50nm
Optical Isolator
Operating wavelength
1550nm±1dB/m
Isolation
≥ 3.0dB/m
Insertion loss
920nm ±50nm
Wavelength selective coupler (WDM)
Operating wavelength
Isolation
19dB (typ)
Insertion loss
1dB (typ)
Optical Circulator
Number of ports
3
Operating wavelength
1530-1570nm
Isolation
35dB (typ)
Insertion loss
1dB (typ)
Fibre Bragg Grating
Bandwidth
20nm
Reflectivity
90% – 95% (typ)