Tan Si, Deng Huiyang, Urbanek Karel E, Miao Yu, Zhao Zhexin, Harris James S, Byer Robert L
Opt Express. 2020 Apr 13;28(8):12475-12486. doi: 10.1364/OE.391036.
The unique properties of gallium oxide (GaO) have drawn increasing interest as a material suitable for high-power electronic and optical applications. Herein, we report the demonstration of low-loss GaO-core/SiO-cladding waveguides on Si substrate. We present the fabrication process and annealing treatments of the waveguide devices, and we characterize the corresponding effects on optical transmission for 3 common wavelengths: 633 nm, 1064 nm, and 1550 nm. The best propagation loss achieved for these wavelengths is measured to be -0.4±0.1dB/cm, -0.3±0.2dB/cm, and -2.4±0.5dB/cm, respectively. We discuss the major waveguide loss mechanisms, followed by results of pump and probe experiments using visible/IR wavelengths for waveguides treated under various post-fabrication annealing conditions. We also show nonlinear measurements for a 250 fs laser beam to offer additional insights into the loss mechanisms, which are consistent with the linear optical transmission performances. High waveguide laser-induced damage threshold (LIDT) of >2.5J/cm is measured at this pulse width, making GaO a potential candidate for high-power integrated photonic devices.
氧化镓（GaO）的独特性质使其作为一种适用于高功率电子和光学应用的材料，受到了越来越多的关注。在此，我们报告了在硅衬底上制备低损耗GaO芯/SiO包层波导的成果。我们介绍了波导器件的制造工艺和退火处理，并对3个常用波长（633 nm、1064 nm和1550 nm）下相应的光传输效果进行了表征。这些波长下实现的最佳传播损耗分别测量为-0.4±0.1dB/cm、-0.3±0.2dB/cm和-2.4±0.5dB/cm。我们讨论了主要的波导损耗机制，随后给出了在各种制造后退火条件下处理的波导使用可见/红外波长进行泵浦和探测实验的结果。我们还展示了针对250 fs激光束的非线性测量结果，以进一步深入了解损耗机制，这些结果与线性光传输性能一致。在此脉冲宽度下，测量得到波导的高激光诱导损伤阈值（LIDT）>2.5J/cm，这使得GaO成为高功率集成光子器件的潜在候选材料。
