近日，美国斯坦福大学的Jelena Vuckovic及其研究团队取得一项新进展。经过不懈努力，他们研制出绝缘体上钛:蓝宝石集成的激光器和放大器。相关研究成果已于2024年6月26日在国际权威学术期刊《自然》上发表。

该研究团队展示了一个单晶绝缘体上的钛:蓝宝石（Ti:SaOI）光子平台，该平台显著提升了Ti:蓝宝石技术的小型化、成本降低和可扩展性。首先，他们通过制造低损耗的回音廊模式谐振器，成功实现了以超低亚毫瓦激光阈值工作的钛蓝宝石激光器。接着，通过大幅改进Ti:SaOI波导模式的约束，研究人员成功研发了工作在1μm以下的集成固态（即非半导体）光放大器。这使得皮秒脉冲在放大过程中几乎无失真，峰值功率高达1.0千瓦，创下了前所未有的纪录。

最后，他们还展示了一款可调谐的集成Ti:蓝宝石激光器，这款激光器能以低成本、微型化和现成的绿色激光二极管进行泵浦。这为Ti:蓝宝石激光器开辟了新的应用前景，比如在大规模可扩展的Ti:蓝宝石激光阵列系统中得到应用。作为概念验证演示，他们使用Ti:SaOI激光阵列作为唯一的光学控制，用于碳化硅中人工原子的腔量子电动力学实验。

这项工作是实现钛蓝宝石技术大众化的关键一步，不仅将成本和占地面积降低了三个数量级，还引入了亚微米波长光的固态宽带放大技术。

据悉，钛蓝宝石激光器对于推进基础研究和技术应用至关重要，包括光学频率梳、双光子显微镜和实验量子光学的发展。钛蓝宝石激光器在带宽和调谐范围方面是无与伦比的，但由于尺寸大、成本高和需要高光泵功率，它们的使用受到限制。

附：英文原文

Title: Titanium:sapphire-on-insulator integrated lasers and amplifiers

Author: Yang, Joshua, Van Gasse, Kasper, Lukin, Daniil M., Guidry, Melissa A., Ahn, Geun Ho, White, Alexander D., Vuckovic, Jelena

Issue&Volume: 2024-06-26

Abstract: Titanium:sapphire (Ti:sapphire) lasers have been essential for advancing fundamental research and technological applications, including the development of the optical frequency comb, two-photon microscopy and experimental quantum optics. Ti:sapphire lasers are unmatched in bandwidth and tuning range, yet their use is restricted because of their large size, cost and need for high optical pump powers. Here we demonstrate a monocrystalline titanium:sapphire-on-insulator (Ti:SaOI) photonics platform that enables dramatic miniaturization, cost reduction and scalability of Ti:sapphire technology. First, through the fabrication of low-loss whispering-gallery-mode resonators, we realize a Ti:sapphire laser operating with an ultralow, sub-milliwatt lasing threshold. Then, through orders-of-magnitude improvement in mode confinement in Ti:SaOI waveguides, we realize an integrated solid-state (that is, non-semiconductor) optical amplifier operating below 1μm. We demonstrate unprecedented distortion-free amplification of picosecond pulses to peak powers reaching 1.0kW. Finally, we demonstrate a tunable integrated Ti:sapphire laser, which can be pumped with low-cost, miniature, off-the-shelf green laser diodes. This opens the doors to new modalities of Ti:sapphire lasers, such as massively scalable Ti:sapphire laser-array systems for several applications. As a proof-of-concept demonstration, we use a Ti:SaOI laser array as the sole optical control for a cavity quantum electrodynamics experiment with artificial atoms in silicon carbide. This work is a key step towards the democratization of Ti:sapphire technology through a three-orders-of-magnitude reduction in cost and footprint and introduces solid-state broadband amplification of sub-micron wavelength light.

DOI: 10.1038/s41586-024-07457-2

Source: https://www.nature.com/articles/s41586-024-07457-2