Abstract In this paper, we introduce a spectrometer design with crossed double-grating for extracting pure rotational Raman (PRR) lines of N2. The design applies a linear optical fibre array as the entrance slit and a linear array photomultiplier tube (LaPMT) as the detector. The linear dispersion and structural parameters of the proposed configuration were analysed theoretically, and the optical layout of the spectrometer was simulated using the Zemax software. A spectrometer with a 32-channel LaPMT was simulated to obtain the PRR spectrum of N2 when the excitation wavelength was 532 nm. The Stokes and anti-Stokes Raman lines, with rotational quantum states from 0 (2) through 14 (16), were obtained on separate channels of the LaPMT, and the resolution was approximately 0.22 nm per channel.

中文翻译：

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用于提取N2纯旋转拉曼谱线的交叉双光栅光谱仪的光学设计

摘要 在本文中，我们介绍了一种具有交叉双光栅的光谱仪设计，用于提取 N2 的纯旋转拉曼 (PRR) 线。该设计采用线性光纤阵列作为入口狭缝，采用线性阵列光电倍增管 (LaPMT) 作为检测器。从理论上分析了所提出配置的线性色散和结构参数，并使用 Zemax 软件模拟了光谱仪的光学布局。模拟具有 32 通道 LaPMT 的光谱仪，以获得激发波长为 532 nm 时 N2 的 PRR 光谱。斯托克斯和反斯托克斯拉曼谱线具有从 0 (2) 到 14 (16) 的旋转量子态，是在 LaPMT 的不同通道上获得的，每个通道的分辨率约为 0.22 nm。