Titanium:sapphire (Ti:sapphire) lasers have been essential for advancing fundamental research and technological applications, including the development of the optical frequency comb¹, two-photon microscopy² and experimental quantum optics^3,4. 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 powers⁵. 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 1 μm. We demonstrate unprecedented distortion-free amplification of picosecond pulses to peak powers reaching 1.0 kW. 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 carbide⁶. 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.

钛:蓝宝石 (Ti:sapphire) 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 ¹ 、双光子显微镜 ² 和实验量子的发展光学 ^3,4 。钛宝石激光器在带宽和调谐范围方面无与伦比，但由于其尺寸大、成本高以及需要高光泵浦功率 ⁵ ，其使用受到限制。在这里，我们展示了单晶钛：绝缘体上蓝宝石 (Ti:SaOI) 光子平台，该平台可实现钛：蓝宝石技术的显着小型化、成本降低和可扩展性。首先，通过制造低损耗回音壁模式谐振器，我们实现了以超低、亚毫瓦激光阈值运行的钛宝石激光器。然后，通过 Ti:SaOI 波导中模式限制的数量级改进，我们实现了工作在 1 μm 以下的集成固态（即非半导体）光放大器。我们展示了前所未有的皮秒脉冲无失真放大，峰值功率达到 1.0 kW。最后，我们展示了一种可调谐集成钛宝石激光器，它可以用低成本、微型、现成的绿色激光二极管进行泵浦。这为钛宝石激光器的新模式打开了大门，例如适用于多种应用的大规模可扩展钛宝石激光器阵列系统。作为概念验证演示，我们使用 Ti:SaOI 激光阵列作为碳化硅中人造原子腔量子电动力学实验的唯一光学控制 ⁶ 。 这项工作通过将成本和占地面积降低三个数量级，并引入亚微米波长光的固态宽带放大，是钛蓝宝石技术民主化的关键一步。