Gallium Oxide for High‐Power Optical Applications

Gallium oxide (Ga2O3) is an emerging wide‐bandgap transparent conductive oxide (TCO) with potential applications for high‐power optical systems. Herein, Ga2O3 fabricated nanostructures are described, which demonstrate high‐power laser induced damage threshold (LIDT). Furthermore, the demonstration of an electron accelerator based on Ga2O3 gratings is reported. These unique Ga2O3 nanostructures provide acceleration gradients exceeding those possible with conventional RF accelerators due to the high breakdown threshold of Ga2O3. In addition, the laser damage threshold and acceleration performance of a Ga2O3‐based dielectric laser accelerator (DLA) are compared with those of a DLA based on sapphire, a material known for its high breakdown strength. Finally, the potential of Ga2O3 thin‐film coatings as field reduction layers for Si nanostructures is shown; they potentially improve the effective LIDT and performance of Si‐based DLAs and other high‐power optical structures. These results could provide a foundation for new high‐power optical applications with Ga2O3. The high laser damage threshold and moderate conductivity of Ga2O3 are leveraged to demonstrate the first Ga2O3‐based laser accelerator and show Ga2O3 as a promising material for high‐power optical applications. With the distinct properties of Ga2O3 combined with advances in fabrication and wafer growth techniques, more Ga2O3‐based high‐power optical applications will be realized in the near future.