Interfacing integrated on-chip waveguides with spectroscopic approaches represents one research direction within current photonics aiming at reducing geometric footprints and increasing device densities. Particularly relevant is to connect chip-integrated waveguides with established fiber-based circuitry, opening up the possibility for a new class of devices within the field of integrated photonics. Here, one attractive waveguide is the on-chip light cage, confining and guiding light in a low-index core through the anti-resonance effect. This waveguide, implemented via 3D nanoprinting and reaching nearly 100% overlap of mode and material of interest, uniquely provides side-wise access to the core region through the open spaces between the cage strands, drastically reducing gas diffusion times. Here, we extend the capabilities of the light cage concept by interfacing light cages and optical fibers, reaching a fully fiber-integrated on-chip waveguide arrangement with its spectroscopic capabilities demonstrated here on the example of tunable diode laser absorption spectroscopy of ammonia. Controlling and optimizing the fiber circuitry integration have been achieved via automatic alignment in etched v-grooves on silicon chips. This successful device integration via 3D nanoprinting highlights the fiber-interfaced light cage to be an attractive waveguide platform for a multitude of spectroscopy-related fields, including bio-analytics, lab-on-chip photonic sensing, chemistry, and quantum metrology.

中文翻译：

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用于气体光谱的光纤集成空心光笼

集成片上波导与光谱方法的接口代表了当前光子学中的一个研究方向，旨在减少几何足迹和增加设备密度。特别相关的是将芯片集成波导与已建立的基于光纤的电路连接起来，为集成光子学领域内的新型器件开辟了可能性。在这里，一个有吸引力的波导是片上光笼，它通过反谐振效应将光限制和引导在低折射率核心中。这种波导通过 3D 纳米打印实现，并达到了感兴趣的模式和材料的近 100% 重叠，独特地提供了通过笼股之间的开放空间进入核心区域的侧向通道，从而大大减少了气体扩散时间。这里，我们通过连接光笼和光纤来扩展光笼概念的功能，实现完全光纤集成的片上波导装置，其光谱能力在此处以氨的可调谐二极管激光吸收光谱为例。控制和优化光纤电路集成是通过在硅芯片上蚀刻的 V 形槽中的自动对齐来实现的。这种通过 3D 纳米打印的成功设备集成凸显了光纤接口光笼成为众多光谱相关领域的有吸引力的波导平台，包括生物分析、芯片实验室光子传感、化学和量子计量学。达到完全光纤集成的片上波导装置，其光谱能力在此处以氨的可调谐二极管激光吸收光谱为例。控制和优化光纤电路集成是通过在硅芯片上蚀刻的 V 形槽中的自动对齐来实现的。这种通过 3D 纳米打印的成功设备集成凸显了光纤接口光笼成为众多光谱相关领域的有吸引力的波导平台，包括生物分析、芯片实验室光子传感、化学和量子计量学。达到完全光纤集成的片上波导装置，其光谱能力在此处以氨的可调谐二极管激光吸收光谱为例。控制和优化光纤电路集成是通过在硅芯片上蚀刻的 V 形槽中的自动对齐来实现的。这种通过 3D 纳米打印的成功设备集成凸显了光纤接口光笼成为众多光谱相关领域的有吸引力的波导平台，包括生物分析、芯片实验室光子传感、化学和量子计量学。