1,000 Times Smaller Than a Grain of Sand – Newest Optical Fiber Technology Could Supercharge Internet Speeds

Swedish researchers have innovated 3D printing by developing silica glass micro-optics on optical fibers, promising faster internet, improved sensors, and advanced imaging systems, while avoiding high-temperature damage to fiber coatings. Credit: David Callahan

Swedish researchers have 3D-printed silica glass micro-optics on optical fibers, enhancing internet speed and connectivity. This technique, more resilient and precise, could revolutionize remote sensing, pharmaceuticals, and photonics.

In a first for communications, Swedish scientists have successfully 3D printed silica glass micro-optics directly onto the tips of optical fibers, areas as tiny as the cross-section of a human hair. This breakthrough could lead to faster internet speeds and enhanced connectivity, along with the development of smaller sensors and more compact imaging systems.

Reporting recently in the journal ACS Nano, researchers at KTH Royal Institute of Technology in Stockholm say integrating silica glass optical devices with optical fibers enables multiple innovations, including more sensitive remote sensors for the environment and healthcare.

The printing techniques they report also could prove valuable in the production of pharmaceuticals and chemicals.

Lee-Lun Lai demonstrates the setup to print silica glass microstructures on an optical fiber. Credit: Lee-Lun Lai demonstrates the setup to print silica glass microstructures on an optical fiber.

Advancements in Printing Techniques

KTH Professor Kristinn Gylfason says the method overcomes longstanding limitations in structuring optical fiber tips with silica glass, which he says often require high-temperature treatments that compromise the integrity of temperature-sensitive fiber coatings. In contrast to other methods, the process begins with a base material that doesn’t contain carbon. That means high temperatures are not needed to drive out carbon in order to make the glass structure transparent.

The study’s lead author, Lee-Lun Lai, says the researchers printed a silica glass sensor that proved more resilient than a standard plastic-based sensor after multiple measurements.

Microscopic image of a printed glass demonstration structure on tip of optical fiber. Credit: David Callahan

“We demonstrated a glass refractive index sensor integrated into the fiber tip that allowed us to measure the concentration of organic solvents. This measurement is challenging for polymer-based sensors due to the corrosiveness of the solvents,” Lai says.

“These structures are so small you could fit 1,000 of them on the surface of a grain of sand, which is about the size of sensors being used today,” says the study’s co-author, Po-Han Huang.

The researchers also demonstrated a technique for printing nanogratings, ultra-small patterns etched onto surfaces at the nanometer scale. These are used to manipulate light in precise ways and have potential applications in quantum communication.

Gylfason says the ability to 3D print arbitrary glass structures directly on fiber tip opens new frontiers in photonics. “By bridging the gap between 3D printing and photonics, the implications of this research are far-reaching, with potential applications in microfluidic devices, MEMS accelerometers, and fiber-integrated quantum emitters,” he says.

Reference: “3D Printing of Glass Micro-Optics with Subwavelength Features on Optical Fiber Tips” by Lee-Lun Lai, Po-Han Huang, Göran Stemme, Frank Niklaus and Kristinn B. Gylfason, 29 March 2024, ACS Nano.
DOI: 10.1021/acsnano.3c11030

The study was funded by the Sweden Taiwan Research Projects 2019 and the Swedish Foundation for Strategic Research.