Page 174 - CITS - Electronic Mechanic - TT - 2024

ELECTRONICS MECHANIC - CITS

Star – It splits the incoming signal into many parts.
Three Port Coupler – It splits the incoming signal into two parts. Here, grin lenses or beam splitter is not used.

While Handling Optical Cables
Never allow a fiber to contact an uncontrolled surface (floor, etc.) where it may be stepped upon, rolled over with
a chair castor, etc. Take care with fingernails and jewelry when handling optical fiber. Gloves or finger cots may
prevent such damage, but also limit the ability to detect damage using tactile senses
Never let a fiber-optic cable hang free from the connector.
Avoid bending fiber-optic cables beyond their minimum bend radius. Bending fiber-optic cables into arcs smaller
than a few inches in diameter can damage the cables and cause problems that are difficult to diagnose.
Applications of Optical Fiber Communications
Fiber optic cables find many uses in a wide variety of industries and applications. Some uses of fiber optic cables
include
• Medical Used as light guides, imaging tools and also as lasers for surgeries
• Defense/Government Used as hydrophones for seismic waves and SONAR , as wiring in aircraft, submarines
and other vehicles and also for field networking • Data Storage Used for data transmission
• Telecommunications Fiber is laid and used for transmitting and receiving purposes
• Networking Used to connect users and servers in a variety of network settings and help increase the speed
and accuracy of data transmission
• Industrial/Commercial Used for imaging in hard to reach areas, as wiring where EMI is an issue, as sensory
devices to make temperature, pressure and other measurements, and as wiring in automobiles and in industrial
settings
• Broadcast/CATV Broadcast/cable companies are using fiber optic cables for wiring CATV, HDTV, internet,
video on demand and other applications Fiber optic cables are used for lighting and imaging and as sensors to
measure and monitor a vast array of variables. Fiber optic cables are also used in research and development.
The optical fibers have many applications. Some of them are as follows
• Used in telephone systems
• Used in sub-marine cable networks
• Used in data link for computer networks, CATV Systems
• Used in CCTV surveillance cameras
• Used for connecting fire, police, and other emergency services.
• Used in hospitals, schools, and traffic management systems.
• They have many industrial uses and also used for in heavy duty constructions
Fiber materials
Most of the fibers are made up of glass consisting of either Silica (SiO2) or .Silicate. High- loss glass fibers are
used for short-transmission distances and low-loss glass fibers are used for long distance applications. Plastic
fibers are less used because of their higher attenuation than glass fibers. Glass Fibers. The glass fibers are
made from oxides. The most common oxide is silica whose refractive index is 1.458_at 850 nm. To get different
index fibers, the dopants such as GeO2, P2O5 are added to silica. GeO2 and P2O3 increase the refractive index
whereas fluorine or B203 decreases the refractive index.
Fiber compositions are given below as follows:
GeO2 – SiO2 Core: SiO2 Cladding
P2Q5 – SiO2, Core; SiO2Cladding
The principle raw material for silica is sand. The glass composed of pure silica is referred to as silica glass, nitrous
silica or fused silica. Some desirable properties of silica are,Resistance to deformation at temperature as high as
1000°C.High resistance to breakage from thermal shock.Good chemical durability.High transparency in both the
visible and infrared regions.

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CITS : E & H - Electronics Mechanic - Lesson 94 - 99