Satellite‐based quantum technologies represent a possible route for extending the achievable range of quantum communication, allowing the construction of worldwide quantum networks without quantum repeaters. In space missions, however, the volume available for the instrumentation is limited, and footprint is a crucial specification of the devices that can be employed. Integrated optics could be highly beneficial in this sense, as it allows for the miniaturization of different functionalities in small and monolithic photonic circuits. This article reports on qualification of waveguides fabricated in glass by femtosecond laser micromachining for their use in a low Earth orbit space environment. In particular, different laser‐written integrated devices, such as straight waveguides, directional couplers, and Mach–Zehnder interferometers, are exposed to suitable proton and γ‐ray irradiation. This experiment shows that no significant changes have been induced to their characteristics and performances by the radiation exposure. These results, combined with the high compatibility of laser‐written optical circuits to quantum communication applications, pave the way for the use of laser‐written integrated photonic components in future satellite missions.

中文翻译：

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超快激光书面集成波导光学器件的空间鉴定

基于卫星的量子技术是扩展量子通信可实现范围的一条可行途径，从而可以在不使用量子中继器的情况下构建全球量子网络。但是，在太空飞行中，可用于仪器的体积是有限的，并且占位面积是可以使用的设备的关键规格。从这个意义上讲，集成光学器件可能会非常有益，因为它可以使小型单片光子电路中的不同功能实现小型化。本文报道了飞秒激光微加工在玻璃中制成的波导在低地球轨道空间环境中的使用资格。尤其是不同的激光集成设备，例如直波导，定向耦合器和马赫曾德尔干涉仪，暴露在合适的质子和γ射线照射下。该实验表明，辐射暴露没有引起其特性和性能的显着变化。这些结果，加上激光写入的光学电路与量子通信应用的高度兼容性，为在未来的卫星飞行中使用激光写入的集成光子组件铺平了道路。