1. Presented by –
Rajen Kumar Maji
Rumpa Mallick
Ankita Kundu
Sayani Sarkar

2.  An Optical fiber is a flexible, transparent fiber
made of high quality glass(silica) or plastic.
 It either functions as a waveguide or light pipe that
transmits light between two ends of the fiber or
fiber cable.
 Optical fibers are widely used in fiber-optic
communication which permits transmission over
long distances at higher bandwidths.
 Fibers are used instead of metal wires because
signal travels along them less loss & also safe to
electromagnetic interference.

3.  Fiber types- Single mode & multimode
 According to refractive index, there are three types of
fiber :
Multimode step index fiber
Multimode graded index fiber
Single mode step index fiber
 Cable construction - There are basic two cable
designs are :
 Tight buffer tube cable
 Loose buffer tube cable

4.  Installation of cables in underground ducts.
 Installation of fiber cables with trenchless
technique.
 Installation of fiber cables with mini trench
technique.
 Installation of fiber cables with micro trench
technique.
 Installation of Aerial cables.
 Installation of Buried cables.
 Installation of fiber cables over power lines.
 Installation of underwater cables.
 Installation of Indoor cables.

5.  There are three types of splicing -
 Adhesive splicing or Glue splicing : This is
the oldest splicing technique use in fiber
splicing.
 Mechanical splicing : This splicing is mainly
used for temporary splicing in case of
emergency repairing.
 Fusion splicing : This is the most popular
technique used for achieving low splice
loss.

6.  Strip fiber cable jacket.
 Strip fiber tubes.
 Clean cable gel.
 Secure cable tubes.
 Strip first splicing
fiber.
 Place the fusion splice
protection sleeve.
 Clean the bare fiber.
 Fiber cleaving. Prepare
second fiber being
spliced.
 Fusion splicing.
 Heat shrinks the
fusion splice
protection sleeve.
 Place splice into
splice tray.
 Perform OTDR test.
 Close the splice
tray.
 Bidirectional OTDR
test(or power meter
test).
 Mount the splice
enclosure.

7.  D4 connector
 SC fiber optic connector
 ST connector
 FC connector
 LC connector
 FDDI connector
 ESCON connector

8. OTDR is a fiber optic tester that
is used to detect, locate and
measure events at any location
in the fiber link.
Components of OTDR—Printer
jack , Pigtail jack, RS232 jack,
Display monitor, Cursor,
Start/LASER switch , Select
switch, Function key.
It operates as a one-dimensional
radar system & generates
geographic information.
It works on back scattering
principle.

9. When a strong reflection occurs, the power received by
the photodiode can be more than 4,000 times higher
than the backscattered power, saturating the
photodiode. The photodiode requires time to recover
from its saturated condition. During this time, it will
not detect the backscattered signal accurately.
 The one at the start of the fiber where the signal is
being launched is called the launch dead zone.

11.  It is a device used to measure the power in an optical signal.
The term usually refers to a device for testing average
power in fiber optic systems.
 The procedure to measure the optical loss in the fiber optic
cable using power meter :
 Connect a short fiber jumper cable between the light source
& the power meter.
 Make note of the power level , in dBm as Reading A
 Connect the fiber cable under test to the output of the source
 Connect the power meter, set the same wavelengths as the
power source, to the far end of the fiber cable under test
 Make note of power level, in dBm as Reading B
 Optical loss = Reading A – Reading B

12.  Optical attenuators use several different
principles in order to accomplish the desired
power reduction
•Gap-loss Principle
•Absorptive Principle
•Reflective Principle
 Types of Attenuators :
•Stepwise variable attenuators
•Continuously variable attenuator

13.  The optical power budget in a fiber-optic communication
link is the allocation of available optical power among
various loss producing mechanisms such as launch
coupling loss, fiber attenuation, splice losses, and connector
losses, in order to ensure that adequate strength is available
at the receiver. The optical power budget is usually
specified or expressed in dB.
 Power budget is the difference between :
The minimum(worst case) transmitter output power
The maximum (worst case) receiver input required