3D Printing of Glass Micro-Optics with Subwavelength Features on Optical Fiber Tips

Abstract

Integration of functional materials and structures on the tips of optical fibers has enabled various applications in micro-optics, such as sensing, imaging, and optical trapping. Direct laser writing is a 3D printing technology that holds promise for fabricating advanced micro-optical structures on fiber tips. To date, material selection has been limited to organic polymer-based photoresists because existing methods for 3D direct laser writing of inorganic materials involve hightemperature processing that is not compatible with optical fibers. However, organic polymers do not feature stability and transparency comparable to those of inorganic glasses. Herein, we demonstrate 3D direct laser writing of inorganic glass with a subwavelength resolution on optical fiber tips. We show two distinct printing modes that enable the printing of solid silica glass structures ("Uniform Mode") and self-organized subwavelength gratings ("Nanograting Mode"), respectively. We illustrate the utility of our approach by printing two functional devices: (1) a refractive index sensor that can measure the indices of binary mixtures of acetone and methanol at near-infrared wavelengths and (2) a compact polarization beam splitter for polarization control and beam steering in an all-in-fiber system. By combining the superior material properties of glass with the plug-and-play nature of optical fibers, this approach enables promising applications in fields such as fiber sensing, optical microelectromechanical systems (MEMS), and quantum photonics.

Ultrafast Laser 3D Nanolithography of Fiber-Integrated Silica Microdevices

“…Recently, polyhedral oligomeric silsesquioxanes (POSS) featuring silicon–oxygen frameworks have found successful applications in the printing of silica glass . When using hydrogen silsesquioxanes as precursors, the hardened gel film state might impose printing constraints. , TPP of fused silica through a sinterless, low-temperature process was realized using POSS and acrylic oligomer composites . Although silica glass with good mechanical and optical properties was manufactured, the direct fabrication of functional silica glass featuring nanometer-scale structures on the optical fiber tip remained unexplored.…”