2. Optical Fiber Fabrication Technology
Optical fiber is used worldwide for transmission of
voice, data, and content because of its ability to transmit
at speeds in excess of 10 GB/second over very long
distances.
3. Optical fibers consist of:
1. A core, having high
refractive index.
2. Cladding.
3. Buffer, protective polymer
layer.
4. Jacket, protective polymer
layer.
4. Types of Fiber Based on
Materials
1. Glass Fibers
2. Plastic Fibers
3. Photonic Crystal Fibers
5. Glass Fibers:
• Glass Is Made by Fusing Mixtures of Metal Oxides, Sulfides or Selenite.
6. • Glass fiber is a dimensionally stable engineering
material. Glass fiber does not stretch or shrink after
exposure to extremely high or low temperatures.
• Glass fibers do not absorb moisture or change physically
or chemically when exposed to water.
• Glass fiber is an inorganic material and will not burn or
support combustion. It retains approximately 25% of its
initial strength at 1000°F (540°C).
7. Plastic Optical Fibers:
• Plastic optical fiber (POF) (or Polymer optical fibre) is an optical
fiber which is made out of Plastic.
• POF standard is based on multilevel PAM modulation a frame
structure, Tomlinson-Harashima Precoding and Multilevel coset coding
modulation.
• For telecommunications, the more difficult-to-use glass optical fiber is more
common.
• Although the actual cost of glass fibers are similar to the plastic fiber, their
installed cost is much higher due to the special handling and installation
techniques required.
12. • Photonic-crystal fiber (PCF) is a new class of optical fiber based on the
properties of photonic crystals.
• PCF is now finding applications in fiber-optic communications, fiber lasers,
nonlinear devices, high-power transmission, highly sensitive gas sensors, and
other areas
• PCFs guiding light by a conventional higher-index core modified by the
presence of air holes.
• Photonic crystal fibers may be considered a subgroup of a more general class
of microstructured optical fibers, where light is guided by structural
modifications, and not only by refractive index differences.
15. • The preform, as mentioned above, is nothing more than an
optical fiber but on a much larger scale.
• Drawing enables the manufacturer to obtain the fiber in the
actual size desired.
• First a Layer of Sio2 Particles Called a Soot is deposited
from a burner onto a Rotating Graphite Or Ceramic
Mandrel.
18. • This was the first successful mass-fabrication process. It was
developed by Corning in 1972. In fact, the first optical fiber with
attenuation less than 20 dB/km was manufactured by Corning using
this process.
• The process consists of four phases: laydown, consolidation, drawing,
and measurement .
21. • This process was developed by Bell Laboratories in 1974 and has
been widely accepted for the production of graded-index fiber.
• First, reactant gases flow through a rotating glass tube made from
fused silica while a burner heats its narrow zone by traveling back
and forth along the tube.
• SiO2, GeO2, and other doping combinations form soot that is
deposited on the inner surface of the target tube.
23. • This process was developed in 1975 by Phillips, a Dutch consumerelectronics and telecommunications company.
• The process differs from MCVD in its method of heating the reaction
zone: Instead of delivering heat from the outside through a burner,
PCVD uses microwaves to form ionized gas—plasma—inside the silica
tube.
• The capacity of this preform is about 30 km of fiber.
