A new process for manufacturing special optical fibers – much simpler, faster and cheaper than traditional ones – was developed by the researcher Cristiano Cordeiro, professor at the Institute of Physics at the State University of Campinas (IFGW-Unicamp).
Cordeiro created the method during a research internship at the University of Adelaide, in Australia, supported by a FAPESP grant, in partnership with Heike Ebendorff-Heidepriem. Article, signed by the two and another collaborator, was published in the journal Scientific Reports, from the Nature group: “Ultra-simplified Single-Step Fabrication of Microstructured Optical Fiber”.
“The conventional process requires enormous and extremely expensive equipment. And it takes almost a week of work. Our process can be carried out with benchtop equipment, at least 100 times cheaper. And it goes from polymer grain to ready-made microstructured fiber in less than an hour. With it, many more researchers and laboratories will be able to produce their own optical fibers”, says Cordeiro to Agência Fapesp.
In very general terms, the procedure is similar to the extrusion method used in the manufacture of noodles: a soft dough is pressed and pushed through a mold; and the thread, with its internal structure, comes out the other end. “Evidently, all of this is done with much greater rigor and precision”, highlights the researcher.
Hundreds of millions of kilometers of optical fibers are currently installed on the planet. And the amount of data they carry doubles approximately every two years. In addition to their use in communications, optical fibers are also used in remote sensing, enabling the monitoring of quantities such as temperature, mechanical traction, hydrostatic pressure, fluid flow, etc. Due to their robustness and small diameter, they have been used successfully in hostile and difficult-to-access environments. Hence the importance of innovating manufacturing methods.
“Conventional production requires a sequence of highly complex steps and equipment, such as the manufacturing tower. It is first necessary to create a macroscopic version of the fiber, two to ten centimeters in diameter. This structure is then heated and controlled by the manufacturing tower. Mass is conserved, and diameter decreases as length increases. Our method greatly simplifies and makes the procedure cheaper. Powered by polymer grains, the device we designed goes from raw material to the final product in a single step,” describes Cordeiro.
The procedure makes it possible to manufacture not only completely solid fibers, in which light is transmitted through a core with a higher refractive index. But also microstructured fibers, which have an arrangement of holes parallel to the longitudinal axis, enabling greater control of optical properties and more functionalities, including the opportunity to guide light with low energy loss in an air channel. To create the microstructures, the researchers use titanium molds with appropriate designs.
“To simplify the manufacturing of special optical fibers, we use equipment and techniques that have become increasingly cheaper and commonplace due to the popularization of 3D printers. The only equipment used is a horizontal extruder, similar to those used to manufacture filaments for 3D printers. This device, no larger than a microwave oven, has an extremely low cost when compared to the manufacturing tower. The titanium mold, with solid parts and holes, is coupled to the extruder outlet”, describes Cordeiro.
Due to its intricate internal structure, the researchers produced the molds through additive manufacturing, using appropriate 3D printers. It is worth noting that this type of manufacturing service can be contracted to specialized companies, so that the only equipment needed to manufacture the fiber is the horizontal extruder.
Read the original content published on the Agência Fapesp website
