We report on the development of a compact (volume $\approx ~100$ cm³), multimode diffraction-limited Raman spectrograph and probe designed to be compact as possible. The spectrograph uses ‘off the shelf’ optics, a custom 3D-printed two-part housing and harnesses a multi-core fibre (MCF) photonic lantern (multimode to few-mode converter), which slices a large 40 $\mu $ m multimode input into a near-diffraction-limited 6 $\mu $ m aperture. Our unique design utilises the hexagonal geometry of our MCF, permitting high multimode collection efficiency with near-diffraction-limited performance in a compact design. Our approach does not require a complex reformatter or mask and thus preserves spectral information and throughput when forming the entrance slit of the spectrograph. We demonstrate the technology over the interval 800 nm to 940 nm (200 cm⁻¹ to 2000 cm⁻¹) with a resolution of 0.3nm (4 cm⁻¹), but other spectral regions and resolutions from the UV to the near infrared are also possible. We demonstrate the performance of our system by recording the Raman spectra of several compounds, including the pharmaceuticals paracetamol and ibuprofen.

中文翻译：

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用于拉曼光谱的基于多芯光纤光子灯的光谱仪

我们报告了紧凑型（卷 $\约~100$ cm ³ )，多模衍射极限拉曼光谱仪和探头设计得尽可能紧凑。该光谱仪使用“现成”光学器件、定制的 3D 打印两部分式外壳，并利用多芯光纤 (MCF) 光子灯笼（多模到少模转换器），将大 40 $\亩 $ m 多模输入到近衍射极限 6 $\亩 $ 米光圈。我们独特的设计利用了 MCF 的六边形几何形状，在紧凑的设计中实现了高多模收集效率和接近衍射极限的性能。我们的方法不需要复杂的重新格式化器或掩模，因此在形成光谱仪的入口狭缝时保留了光谱信息和吞吐量。我们在 800 纳米到 940 纳米（200 厘米^-1到 2000 厘米^-1）范围内展示了该技术，分辨率为 0.3纳米（4 厘米^-1），但其他光谱区域和从紫外到近红外的分辨率是也可以。我们通过记录几种化合物（包括药物扑热息痛和布洛芬）的拉曼光谱来证明我们系统的性能。