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
Optical fibers consist of:
1. A core, having high
3. Buffer, protective polymer
4. Jacket, protective polymer
Types of Fiber Based on
1. Glass Fibers
2. Plastic Fibers
3. Photonic Crystal Fibers
• Glass Is Made by Fusing Mixtures of Metal Oxides, Sulfides or Selenite.
• 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).
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
• For telecommunications, the more difficult-to-use glass optical fiber is more
• 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
Photonic Crystal Fibers:
• 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
• 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.
• 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
Vapor-Phase Axial Deposition (VAD):
• 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
• The process consists of four phases: laydown, consolidation, drawing,
and measurement .
Modified Chemical Vapor Deposition(MCVD):
• 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.
Plasma-Activated Chemical Vapor Deposition(PCDV):
• 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
• The capacity of this preform is about 30 km of fiber.