Fiber Optic Testing | Fiber Optic Test and Measurement

This page on fiber optic testing covers various types of testing related to fiber optic communication link.

Fiber optic communication system consists of transmitter part, fiber optic cable as transmission medium and receiver part. Transmitter part will have LED (Light Emitting Diode) which converts digital binary data into light waves. Receiver part will have photo diode or detector which converts light waves into digital binary data. Coder and decoder is interfaced when needed.

Fiber optic communication has several benefits over other transmission methods e.g. copper and data communication etc.
• Signal can be transmitted to longer distances(about 200 Km) without the need of re-generation.
• The transmission is unaffected from any Electro-Magnetic Perturbations or RF interferences.
• Fiber optic cable has higher capacity compare to copper or coaxial cables.
• Fiber optic cable is lighter and smaller compare to copper cable.
• Optical fiber is not sensitive to any kind of vibrations.
• Optical fiber is reliable.

There various factors which affect light transmission in Fibre optic communication system➤. They are attenuation, Bandwidth and dispersion.

Attenuation:As light travels from transmit end to receive end, it loses optical power due to absorption, scattering and radiation losses. Sometimes it becomes difficult to recognize and decode the optical signal due to presence of noise.

Bandwidth:As we know light signal is composed of different frequencies. Hence fiber will have both upper and lower frequencies which will limit the information carrying capacity of the optical fiber cable.

Dispersion:When light signal traverses fiber , pulses of light waves will get spread and hence will limit the information carrying capacity at high bit rates or transmission over long distances.

fiber optic communication tutorial

While analyzing fiber optic cable, series of measurements are being performed. These include following tests:
• 1. Mechanical Tests
• 2. Geometrical Tests
• 3. Optical Tests
• 4. Transmission Tests

The first of the three measurements listed above are measured just once as there will be very minor variations in the measurement results over the lifetime of the fiber optic cable.

Mechanical Tests Geometrical Tests Optical Tests Transmission Tests
Core Diameter
Index Profile
Numerical Aperture
Spot Size
Optical Power
Optical Loss
Optical Return Loss
Chromatic Dispersion
Polarization Mode Dispersion
Attenuation Profile

Reference: ITU-T G650 EN 188 000 Fiber Optic Testing and test procedure

Fiber Optic Related Links

DWDM system basics   Fibre optic communication   Types of WDM   PDH versus SDH   SONET versus SDH   What is PDMA?   What is WDM?   SONET SDH tutorial   SDH Networks   SDH Frame structure   SDH Modulation   PDH over SONET   PDH Frame structure  Optical Components 

Test and Measurement Equipments

This section covers test and measurement equipments for WLAN, WiMAX, zigbee, Bluetooth, GSM, UMTS, LTE and more standard based device testing. It covers spectrum analyzer, VSG, VSA, frequency counter, protocol analyzer, AWG, digitizer, function generator, pulse generator, RF network analyzer, power meter, logic analyzer and more.
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