Researchers describe new technique to print transparent ceramics

In new research reported in Optics Letters and featured by the journal as an Editors’ Pick, LLNL researchers describe a new technique to print transparent ceramics with extremely fine feature sizes (in the tens of microns) for use as laser-amplification media. This technique is particularly amenable to thin film geometry and enables control of the composition and location of each droplet, offering flexibility and precision in the compositional profile of the structure.

The team fabricated the laser waveguides using a jet valve equipped with a nozzle on a three-axis dispensing stage. There they loaded yttrium–aluminum–garnet (YAG) nanoparticles doped with ytterbium into an ink with the help of a dispersant and binder and ultrasonicated it to form a colloid. They then took measurements on a variety of ink formulations to optimize the inks, resulting in successful droplet formation and printing resolution. This printing technique not only allows the deposition of uniform films with controlled thickness, but also opens the path to more complex structures.

To demonstrate laser performance, the team printed planar waveguides with guide thickness ranging between 25 and 350 micrometers and consolidated them to high optical quality via solid-state sintering. Sufficiently low optical and intermodal scatter allowed single-mode propagation. Additionally, the researchers pumped the waveguides longitudinally with a 940-nanometer diode array, resulting in 23.6% slope efficiency in 2 milliseconds pulsed operation.

The Laboratory Directed Research and Development Program supported this work (19-ERD-006).

[Z.M. Seeley, I.R. Phillips, T.J. Rudzik, N.J. Cherepy, A.D. Drobshoff, and S.A. Payne, Material jet printing of transparent ceramic Yb:YAG planar waveguides, Optics Letters 46 (10) 2433 (2021).]