论文标题
部分可观测时空混沌系统的无模型预测
An on-chip astrophotonic spectrograph with a resolving power of 12,000
论文作者
论文摘要
随着即将到来的极大望远镜（ELT），相关光谱仪的体积，质量和成本将随望远镜直径而扩展。 Astrophotonics在芯片上以单模纤维馈线限制光谱仪的形式为此问题提供了独特的解决方案。这些高度微型芯片在光子的连贯操作方面具有极大的灵活性。这种光子光谱仪非常适合从直接成像的行星（使用单模纤维收集）中分散光线的光，以表征系外行星大气。在这里，我们介绍了使用阵列的波导格栅（AWG）体系结构的概念验证高分辨率的天体光谱仪的结果。该芯片使用低损失的罪恶平台（Sin Core，Sio $ _2 $ cladding）和方波导（800 nm $ \ times $ 800 nm）。 AWG具有$ \ sim $ 12,000的测量分辨率（$λ/δλ$），而自由光谱范围（FSR）为2.8 nm。虽然FSR很小，但芯片在宽带（1200美元 - $ 1700 nm）上运行。片上芯片量的峰值（不包括耦合效率）为$ \ sim $ 40 \％（-4 dB），在TE模式下，总吞吐量（包括耦合损失）为$ \ sim $ 11 \％（-9.6 dB）。得益于高浓度的波导几何形状，该芯片被高度微型化，尺寸仅为7.4毫米$ \ times $ 2毫米。 该演示凸显了天体平台的罪恶平台的实用性，尤其是商业罪铸造厂在适用于地面和太空望远镜的芯片上制造超小型，高分辨率，高通量AWG光谱仪的能力。
With the upcoming extremely large telescopes (ELTs), the volume, mass, and cost of the associated spectrographs will scale with the telescope diameter. Astrophotonics offers a unique solution to this problem in the form of single-mode fiber-fed diffraction-limited spectrographs on a chip. These highly miniaturized chips offer great flexibility in terms of coherent manipulation of photons. Such photonic spectrographs are well-suited to disperse the light from directly imaged planets (post-coronagraph, collected using a single-mode fiber) to characterize exoplanet atmospheres. Here we present the results from a proof-of-concept high-resolution astrophotonic spectrograph using the arrayed waveguide gratings (AWG) architecture. This chip uses the low-loss SiN platform (SiN core, SiO$_2$ cladding) with square waveguides (800 nm $\times$ 800 nm). The AWG has a measured resolving power ($λ/δλ$) of $\sim$ 12,000 and a free spectral range (FSR) of 2.8 nm. While the FSR is small, the chip operates over a broad band (1200 $-$ 1700 nm). The peak on-chip throughput (excluding the coupling efficiency) is $\sim$40\% (- 4 dB) and the overall throughput (including the coupling loss) is $\sim$ 11\% (- 9.6 dB) in the TE mode. Thanks to the high-confinement waveguide geometry, the chip is highly miniaturized with a size of only 7.4 mm $\times$ 2 mm. This demonstration highlights the utility of SiN platform for astrophotonics, particularly, the capability of commercial SiN foundries to fabricate ultra-small, high-resolution, high-throughput AWG spectrographs on a chip suitable for both ground- and space-based telescopes.
