Liu Yang, Li Jinhuan, Zhang Pengfei, Zhou Aiming, Wang Xiaoxu, Wang Junbo, Li Bo, Lin Guanyu, Gu Guochao, Li Hanshuang
Opt Express. 2023 Oct 9;31(21):35054-35067. doi: 10.1364/OE.502867.
Immersion gratings have high dispersion efficiency and have important application value in miniaturized imaging spectrometers, but its serious dispersion nonlinearity causes difficulties in calibration and image processing, which limits its application range. To solve this, this paper presents a design method for a two-material linear dispersion immersion grating device design method, and a compact small F-number immersion grating spectrometer based on it. First the vector form dispersion equation of the two-material immersion grating is derived and the linear spectral dispersion immersion grating design process is given, then a compact small F-number uniform dispersion imaging spectrometer is given as a design example using the proposed method. The results show that when the operating band of the system is 1590-1675 nm, the spectral resolution is better than 0.25 nm, and F-number can achieve better than 2. Compared with traditional single-material immersion grating imaging spectrometer, the designed imaging spectrometer dispersion linearity is significantly improved. Finally, the influence of prism materials, structure parameters and grating parameters on dispersion nonlinearity is analyzed. Design and analysis results show that the proposed two-material immersion grating device has much better spectral dispersion nonlinearity correction ability, and its design method can provide reference to the compact spectrometer design based on immersion gratings.
浸没光栅具有高色散效率，在小型化成像光谱仪中具有重要应用价值，但其严重的色散非线性给校准和图像处理带来困难，限制了其应用范围。为解决这一问题，本文提出了一种双材料线性色散浸没光栅器件的设计方法，并基于此设计了一种紧凑的小F数浸没光栅光谱仪。首先推导了双材料浸没光栅的矢量形式色散方程，给出了线性光谱色散浸没光栅的设计过程，然后以所提方法为例给出了一种紧凑的小F数均匀色散成像光谱仪。结果表明，当系统工作波段为1590 - 1675 nm时，光谱分辨率优于0.25 nm，F数可达到优于2。与传统单材料浸没光栅成像光谱仪相比，所设计的成像光谱仪色散线性度显著提高。最后分析了棱镜材料、结构参数和光栅参数对色散非线性的影响。设计与分析结果表明，所提双材料浸没光栅器件具有更好的光谱色散非线性校正能力，其设计方法可为基于浸没光栅的紧凑光谱仪设计提供参考。
