A new 3D printing method could make ceramic laser waveguides easier to manufacture, potentially enabling higher-power systems while reducing fabrication challenges and improving design flexibility.
Lawrence Livermore National Laboratory (LLNL) has demonstrated a 3D-printing approach for producing yttrium aluminium garnet (YAG) ceramic laser waveguides, potentially offering a simpler route to structures designed to handle higher optical power.
The researchers used a technique called direct ink writing, in which a nanoparticle-loaded YAG paste is extruded as thin filaments. This allows the team to form laser-guiding channels and their surrounding cladding in a single manufacturing process, rather than fabricating the components separately.
Waveguides are carefully designed paths for light, with a central core surrounded by cladding. Differences between the two materials keep light confined so it can travel through the structure. Producing these tiny structures from ceramics has traditionally been difficult because of the precision required during fabrication.
The new method begins by printing a three-dimensional structure from the nanoparticle paste. The printed component is then dried, sintered and hot-isostatically pressed to create a transparent ceramic. Because the core and cladding are produced together, the process can achieve high fabrication yield while reducing defects at the interface.
The researchers produced three waveguides within a single ceramic block. Tests showed that the waveguides could carry laser light, with the cladding producing low optical losses. The best-performing waveguide had an elliptical cross-section measuring 100 by 60 micrometres and was 1.4 centimetres long.
The work could eventually help make ceramic components for higher-power laser systems, particularly where conventional materials face limitations. The researchers say the approach could also make the advantages of crystalline ceramics easier to exploit.
However, the technology remains at an early research stage. LLNL still needs to improve the fabrication process, scale up the laser power and determine whether the ceramic waveguides can maintain their optical performance under much higher loads. The study was published in Optics Letters.
