Maintenance of Fiber Systems
Fiber optic networks require little maintenance once they are up and running. The most difficult task is setting up the network properly. Things to remember when working with a fiber optic network are
• Proper test equipment. Trouble shooting an optical network is next to impossible without the proper equipment. Make sure you have a properly calibrated optical power meter, fiber cleaners and good optical fiber cables
• Clean all fiber mating surfaces before connection. Every time a fiber is removed from a mating sleeve it must be cleaned with a proper fiber cleaning apparatus before being replaced
• Never touch the end of a fiber optic. Finger prints interfere with optical signals
• Keep fiber tie wraps loose and keep a minimum bending radius of 5cm on all fiber pigtails
• Never pinch or introduce a sharp bend in the fiber
• Know your network. Make sure you know the attenuation and ORL of your fiber system. Do have enough link budgets for the receivers?
• If a link goes down:
o Verify the transmitter has a valid electrical input signal
o Verify all jumpers are properly installed and transmitter is configured properly
o Check the output optical power of the transmitter with a power meter.
o Verify the optical power at the receiver with an optical meter
o Verify dispersion limit of system is not violated
o Verify transmitter and receiver are properly seated in frame
o Clean all accessible fiber jumpers in the system
Optical Network Components
There are many different active and passive components that make up an optical network. A solid understanding of the function of these components is vital when designing a cost-effective optical network that will meet the bandwidth needs for many years to come.
The Coupler
The optical coupler is often called a splitter and is depicted in Figure 1. It is a passive optical component (requires no power to operate) that can divide or combine light power between multiple fibers. There are many types of couplers available; the most commonly used are the 50/50, 80/20 and the 90/10. The numbers designate the percentage of light power divided between the outputs. Other coupler types split incoming optical signals among multiple outputs. Couplers are bi-directional and can combine multiple optical signals on to a single fiber, however this will introduce some loss in the system. Evertz’s passive optical couplers are available in many commonly used splitter types to meet the requirements for many optical systems.
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| Figure 1: A 50/50 passive optical coupler evenly distributes an incoming optical signal applied to its common port between its two output ports |
