Optical fiber production process


There are more than ten methods for producing quartz op […]

There are more than ten methods for producing quartz optical fiber preforms in the world. Among them, there are four main methods for making high-quality optical fibers:
--- Improved chemical vapor deposition (MCVD: Modified Chemical Vapour DepositiON)
---Vapour phase Axial Deposition (VAD: Vapour phase Axial Deposition)
---Outside Chemical Vapour Deposition (OVD: Outside Chemical Vapour Deposition)
---(Microwave) Plasma Activated Chemical Vapour Deposition (PCVD)
According to the traditional naming method, the current four technologies in the optical fiber technology market coexist, namely OVD, VAD, MCVD, and PCVD. However, simply using the above process name to simply indicate that the current production process is already very incomplete. The current vapor phase deposition processes for commercial production of optical fiber preforms have evolved into "Two-step Processes." Among them, the process names such as OVD and MCVD only indicate the first step of producing the preform, that is, the process used for producing a core rod (Core-rod/Primary Preform/Initial Preform).
In the production of mandrel, not only the core but also the partial cladding must be made. This is to ensure the optical quality of the fiber. Subsequently, the mandrel can be thinned into many small core rods or not, depending on the core. The size of the stick. In the second step, an outer layer (commonly known as outsourcing technology or Overcladding) is attached to the mandrel to make a preform. Before drawing, the preform can be thinned or not, depending on the size of the preform and the drawing furnace.
Therefore, the so-called "two-step method" is not limited to two steps, the optical characteristics of the optical fiber preform mainly depends on the mandrel manufacturing technology; the cost of the optical fiber preform depends mainly on the outsourcing technology, therefore, the mandrel manufacturing technology plus the outsourcing technology In order to fully explain the characteristics of the current fiber preform manufacturing process.