AI 中文总结
研究针对天文干涉测量在J和H波段的宽带分光和耦合问题，提出宽带倏逝三耦合器等组件，利用氮化硅和氧化硅平台及定制锥形组件，实现相关功能并给出实验结果，为未来中红外平台的光束组合器发展奠定基础。
AI 中文摘要
被动和主动光子组件对于天文光子集成电路（PIC）的持续发展至关重要，尽管实现宽带消色差性能仍是重大挑战。本文介绍了用于J和H波段天文干涉测量的宽带倏逝三耦合器、锥形定向耦合器以及色度控制消色差强度调制器。氮化硅和氧化硅提供了互补的低损耗平台，定制的锥形组件实现了0.95 - 1.8微米范围内的宽带运行。针对意法半导体开发的氮化硅平台，设计了锥形三耦合器和定向耦合器替代PLANETS项目中配对光束组合器的传统组件。优化后的锥形三耦合器在J波段的额外损耗小于1%，锥形定向耦合器提供适合光束组合的宽带40:60分光。对于Enablence的氧化硅平台，研究了二维锥形三耦合器用于消零干涉测量。该器件在H波段提供宽带星光抑制，同时将系外行星通量损失限制在小于2.2%，并保留用于条纹跟踪的宽带相位传感能力。色度控制消色差强度调制器由锥形定向耦合器和热光移相器组合而成，为干涉PIC中的应用提供可编程宽带强度控制。未来工作将把这些概念扩展到在中红外运行的光刻制造硫系玻璃平台，为未来针对类地系外行星的地基和空基消零干涉仪实现紧凑的光子光束组合器。
英文摘要
Passive and active photonic components are central to the continued development of astronomical photonic integrated circuits (PICs), although achieving broadband achromatic performance remains a significant challenge. This work presents broadband evanescent tri-couplers, tapered directional couplers, and a chromatically controlled achromatic intensity modulator for astronomical interferometry in the J- and H-bands. Silicon nitride and silicon oxide provide complementary low-loss platforms, while customised tapered components enable broadband operation across the 0.95-1.8 microns range. For the silicon nitride platform developed by STMicroelectronics, tapered tri-couplers and directional couplers were designed as replacements for conventional components in a pairwise beam combiner for the PLANETS project. Optimised tapered tri-couplers achieve less than 1% excess loss across the J-band, while tapered directional couplers provide broadband 40:60 splitting suitable for beam combination. For the silicon oxide platform from Enablence, a two-dimensional tapered tri-coupler was investigated for nulling interferometry. The device provides broadband starlight suppression while limiting exoplanet throughput loss to less than 2.2% across the H-band and simultaneously retaining broadband phase-sensing capability for fringe tracking. The chromatically controlled achromatic intensity modulator is introduced as a combination of a tapered directional coupler with a thermo-optic phase shifter, the device provides programmable broadband intensity control for applications including null-depth balancing in interferometric PICs. Future work will extend these concepts to lithographically fabricated chalcogenide glass platforms operating in the mid-infrared, enabling compact photonic beam combiners for future ground- and space-based nulling interferometers targeting Earth-like exoplanets.
Comments21 pages, 23 figures, SPIE Astronomical Telescopes + Instrumentation 2026 Denmark
