Draw Tower Gratings (DTG®s) are produced using a procedure that integrates the drawing of the optical fiber with the writing of the grating.
DTG® Production Process
The figure below illustrates the arrangement of this production process. The input of the process is a glass pre-form. Once the pre-form is heated, the pulling and formation of the fiber will be started.
Also in the production process, the fiber crosses the optical axis of a laser and the interferometer that produces a periodical UV-light interference pattern so as to write the grating. Using a pulse selector and taking into consideration the draw speed, FBGs can be accurately placed in the fiber.
After the grating has been written, the fiber is coated by entering a coating reservoir, which is followed by a-curing step of the coating.
Lastly, the FBG’s location is marked automatically and the fiber is reeled onto a drum.
This method of simultaneously drawing the fiber, writing the grating and coating the fiber directly after the grating inscription, produces high strength grating chains.
As such, the frequently used stripping and recoating process of regular FBGs is not essential and the pristine fiber strength is preserved during the DTG® manufacturing process.
This information has been sourced, reviewed and adapted from materials provided by FBGS Technologies GmbH.
For more information on this source, please visit FBGS Technologies GmbH.