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to intermediate-distance applications, such as within a building
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It features a core diameter of 8 to 9 microns
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(22)
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A glass fiber guides the optical AV signal along its path
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(23)
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An LED that emits visible light is used in a variety of applications, including signage, area
lighting, numerical displays, and indicator lights on electrical equipment
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An LED
is not recommended for transmitting high speed video signals over fiber
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In AV fiber optic transmitters, laser diodes are used as the light source for
transmitting video, audio, and control signals
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what is a VCSEL?
VCSEL stands for Vertical Cavity Surface Emitting Laser
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It can be mass-produced with high yield rates
and has a smaller PCB footprint, making it ideal for use in fiber optic transmitters to send high resolution
video, audio, and control signals
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A
photodetector is used in a fiber optic receiver to convert optical AV signals
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The
most common wavelengths are 850 nm and 1300 nm due to the availability of low cost semiconductor light
sources and photo detectors
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At 1310 nm, chromatic dispersion is near zero,
and at 1550 nm, attenuation is near its minimum
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OS2 singlemode fiber is capable of
transmitting any wavelength above its cutoff wavelength, which is typically around 1250 nm
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Above the cutoff wavelength, singlemode fiber propagates only one mode
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(30) How is an electrical AV signal converted into an optical AV signal?
An electrical AV signal is converted into an optical AV signal using an optical transmitter or an electrical-tooptical converter
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For an analog signal, the intensity of the light source
varies with the voltage or current of the electrical signal
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(31) How is an optical AV signal converted back into an electrical AV signal?
An optical signal is converted into an electrical signal using an optical receiver or an optical-to-electrical
converter
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(32)
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It is difficult to compensate for these distortions
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When the dimmed optical signal is converted back into
an electrical signal, the voltage levels are too low
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Fiber optic AV equipment that uses analog
techniques suffers from increased noise and distortion, which produces a low quality video signal
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How does Extron handle analog video signals in its fiber optic products?
Extron fiber optic products convert analog signals to digital signals for an all-digital transmission of video,
audio, and control signals
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(34)
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Newer, laser-optimized multimode fiber may extend
transmission distances up to 2 km
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(35) What AV applications require fiber technology?
Fiber optical technology is ideal when transmitting video, audio, and control signals over long distances, in
secure or hazardous environments, or anywhere where it is important to future-proof an AV system
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Low
signal emissions make fiber optic products preferred for secure environments such as military or
government applications
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(36) What are the advantages of fiber AV systems in large venues and long haul transmissions?
Optical fiber is low-loss compared to electrical wire, and can transmit a signal over very long distances
without the need of a repeater
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(37) What are the advantages of fiber optic AV systems in government applications?
Copper wires emit electrical signals that can be picked up with special listening equipment
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Because optical fiber is immune to
electrical interference and has zero electrical emissions, it is preferred over copper wire to carry sensitive
information
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Since optical fiber is made of glass, it can also be used to transmit information between
secure facilities that are electrically isolated
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Additionally, high-voltage video displays must be isolated from medical imaging machines
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This type of mounting system requires that the cabling medium be small but also
strong
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(69) What considerations exist when joining fibers using a connector?
Special care must be taken when connecting and disconnecting optical cables to avoid damaging the fiber
or the connector on the device
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The fiber and connector should be cleaned prior to mating
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(70) When do I clean the fiber optic connectors?
Both the fiber and connector ends should be cleaned immediately before mating
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(71) Why do I need to clean fiber optic connectors?
Even in clean environments, a single dust particle could completely block an optical signal
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(72)
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The swabs are for cleaning inside of
the connector on an instrument
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(73) Can fiber optic light cause harm?
Although the light used for fiber optic transmission is in the infrared range and is not visible to the human
eye, it can still cause damage
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Avoid
looking into a fiber if it is unknown whether there is an active light source
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The most appropriate method depends on the optical loss budget, the application type, what
equipment is available, and the skills of the repair technician
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A connector splice is generally used when another component or device must be
installed in line with the fiber
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Index matching gel is used to hold the cores together
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This produces a very low-loss connection that is superior to a mechanical splice
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(77) How do you identify the type of dark fiber installed if it is poorly documented?
The color of the fiber jacket may identify the type of fiber
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Cable markings may also help identify the manufacturer and type of cable
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However, field testing to (78)
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If the fiber optic cable includes a metallic armor, it is marked as OFCP for Optical Fiber
Conductive Plenum
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If the fiber optic cable includes a metallic armor, it is marked as OFCR for
Optical Fiber Conductive Riser
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(ii) Here waves should be of the same frequency
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(iv) The amplitudes of both the waves should also be the same

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