High-resolution and compact serpentine integrated grating spectrometer
High-resolution and compact serpentine integrated grating spectrometer
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DOI：
10.1364/josab.423968
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发表时间：
2021-07
影响因子：
1.9
通讯作者：
M. Brand;Bohan Zhang;Deniz Onural;Kenaish Al Qubaisi;M. Popović;N. Dostart;K. Wagner
中科院分区：
文献类型：
--
作者：
M. Brand;Bohan Zhang;Deniz Onural;Kenaish Al Qubaisi;M. Popović;N. Dostart;K. Wagner
集成天文光子光谱仪是传统自由空间光谱仪的集成变体，其提供显著减小的尺寸、重量和成本以及对对准误差的免疫力，并且可以容易地与其他天文光子仪器（例如调零干涉仪）集成。目前的色散型集成天文光子光谱仪都是一维器件，如阵列波导光栅或平面中阶梯光栅。这些装置由于具有有限的总光学延迟路径和1D检测器阵列像素密度而被限制为104分辨能力和<1000光谱箱。在本文中，我们提出并证明了一个高分辨率和紧凑的空间光子蛇形集成光栅（SIG）光谱仪的设计的基础上，二维色散蛇形光学相控阵列。SIG器件将5.2 cm长的折叠延迟线与光栅耦合器相结合，以在紧凑的集成器件覆盖区中沿沿着两个维度创建大的光学延迟路径。类似于自由空间交叉色散高分辨率光谱仪，SIG光谱仪将光谱内容映射到聚焦到2D检测器阵列上的2D波长光束转向折叠光栅发射图案。我们展示了一台具有100 k分辨率和106750个光谱箱的SIG光谱仪，比之前在宽带宽上工作的集成光子设计高出大约一个数量级，占地面积为0.4mm 2。我们测得的瑞利分辨率为1.93 ± 0.07GHz和工作带宽为1540 nm至1650 nm。最后，我们讨论了改进的SIG光谱仪，提高其分辨率，带宽和吞吐量。这些结果表明，SIG光谱仪技术为天文学及其他领域的小型化、高分辨率光谱仪提供了一条途径。
Integrated astrophotonic spectrometers are integrated variants of conventional free-space spectrometers that offer significantly reduced size, weight, and cost and immunity to alignment errors, and can be readily integrated with other astrophotonic instruments such as nulling interferometers. Current integrated dispersive astrophotonic spectrometers are one-dimensional devices such as arrayed waveguide gratings or planar echelle gratings. These devices have been limited to 104 resolving powers and <1000 spectral bins due to having limited total optical delay paths and 1D detector array pixel densities. In this paper, we propose and demonstrate a high-resolution and compact astrophotonic serpentine integrated grating (SIG) spectrometer design based on a 2D dispersive serpentine optical phased array. The SIG device combines a 5.2 cm long folded delay line with grating couplers to create a large optical delay path along two dimensions in a compact integrated device footprint. Analogous to free-space crossed-dispersion high-resolution spectrometers, the SIG spectrometer maps spectral content to a 2D wavelength-beam-steered folded-raster emission pattern focused onto a 2D detector array. We demonstrate a SIG spectrometer with ∼100k resolving power and ∼6750 spectral bins, which are approximately an order of magnitude higher than previous integrated photonic designs that operate over a wide bandwidth, in a 0.4mm2 footprint. We measure a Rayleigh resolution of 1.93±0.07GHz and an operational bandwidth from 1540 nm to 1650 nm. Finally, we discuss refinements of the SIG spectrometer that improve its resolution, bandwidth, and throughput. These results show that SIG spectrometer technology provides a path towards miniaturized, high-resolution spectrometers for applications in astronomy and beyond.