Optical fiber production begins with a preform. Silica is commonly used to make optical fiber ,
because it has good transmission over a wide range of wavelengths and low absorption and scattering losses (~0.2 dB/km).
Silica is also highly resistant to both mechanical and optical damage. The core/clad ratio of the preform is maintained during the draw process.
The resulting optical fiber has this same core/clad ratio.The silica fiber production facility in Hicorpwell uses cylindrical silica preforms.
It can withstand pulling and bending as well as amplified laser pulses.
Our Hicorpwell optical fiber in one of two ways: drawing a preform containing a glass core and a glass clad or drawing a pure silica rod
and coating the resulting fiber with an optical polymer as the cladding.
The preform is prepared for draw on the glass-working lathe.
The handle end is chucked, or loaded, into the top-feed unit located at the top of the tower.
The top-feed unit lowers the preform into the furnace, and the heating process begins.
This inline furnace has a graphite element that surrounds, but does not touch, the preform.
The graphite allows the heat to be evenly distributed around the glass cylinder.
High-purity, oxygen-free Argon gas is cycled through the furnace to protect the graphite element at high temperatures.
The furnace slowly heats up the preform. As the temperature rises, the preform will start to glow.
This bright orange glow is caused by the heat of the furnace and will scatter at the weld between the handle and the preform.
The preform transmits light similarly to the optical fiber it will become.
Once the furnace reaches about 2000 °C, the drop end of the preform begins to fall under gravity through the hole in the bottom of the furnace.
The drop end is what remains after a quartz handle has been removed after firepolishing.
A technician cuts the drop end off the glass flow and begins to pull the newly drawn fiber out of the furnace.
He tapes a small weight to the end of the glass and threads it through the rest of the apparatuses along the length of the tower and into the capstan puller.