基于偏振干涉成像光谱仪的视场增强和相位热漂移补偿关键技术的研究

发布时间：2018-01-08 10:35

本文关键词：基于偏振干涉成像光谱仪的视场增强和相位热漂移补偿关键技术的研究　出处：《光谱学与光谱分析》2016年11期 　论文类型：期刊论文

【摘要】：偏振干涉成像光谱技术以傅里叶变换光谱学为理论基础,以一系列起偏/检骗器、剪切分束器和延时晶体等双折射晶体材料为主要结构,较之传统光栅式色散型光谱仪具有多通道、图谱合一、大光通量、高信噪比和抗环境振动干扰等一系列优点,并且结合多普勒光谱学相关原理和技术,已被广泛应用在各种天文学和天体物理学测试与计量领域如空间遥感、视向速度、宇航飞行、月球探测等。但是许多前人研究工作中仍然存在两个尚未妥善解决的问题:(1)视场受限。普通型偏振干涉成像光谱仪存在远场条纹的弯曲而使系统视场角限制在±2°以内,严重影响傅里叶变换后的光谱重构精度;(2)相位热漂移。晶体的热胀冷缩和双折射率之差随温度变化的特性导致像面干涉条纹发生随机抖动误差,将严重影响以多普勒频移为原理的视向速度等测量精度。因此,首先引入一块半波片构成增强型的Savart剪切分束器实现主动的视场展宽,可以使增强后的观察视场角达到±10°左右。这一改进不仅提高了傅里叶光谱变换的算法精度,同时也大幅增加光通量从而实现对微光光谱进行高信噪比的探测与标定。另外,为了消除环境温度造成的相位热漂移误差,选用偏硼酸钡(α-BBO)和铌酸锂(LiNbO3)两种晶体进行精密组合匹配。该关键技术利用这两种晶体的双折射率之差随温度变化的相反特性,从而实现相位热漂移误差补偿。实验证明,在实验室环境温度下热相位漂移误差不超过0.02rad。通过这些方案改善偏振干涉成像光谱仪的测试精度,拟实现对天文光梳以及其他大型天文光谱仪器快速而精确的标定与测试。
[Abstract]:Polarization interference imaging spectroscopy is based on Fourier transform spectroscopy and is composed of a series of birefringent crystal materials such as polarizer / detector shearing beam splitter and delay crystal. Compared with the traditional grating dispersive spectrometer, it has a series of advantages, such as multi-channel, unifying spectrum, large luminous flux, high signal-to-noise ratio (SNR) and anti-environment vibration interference, and combined with the related principles and techniques of Doppler spectroscopy. It has been widely used in various fields of astronomy and astrophysics testing and metrology, such as space remote sensing, apparent velocity, aerospace flight. Lunar exploration, etc. But there are still two unsolved problems in many previous research work: 1). The field of view is limited. The conventional polarization interference imaging spectrometer has the bending of far field fringes, which limits the angle of view of the system to 卤2 掳. The spectral reconstruction accuracy after Fourier transform is seriously affected. (2) Phase thermal drift. The difference between thermal expansion, cold contraction and birefringence varies with temperature, which results in random jitter error of image plane interference fringes. The measurement accuracy such as apparent velocity based on Doppler frequency shift will be seriously affected. Therefore, an enhanced Savart shearing beam splitter composed of a half-wave plate is introduced to realize active field broadening. The enhanced field of view angle can reach 卤10 掳, which not only improves the accuracy of Fourier transform algorithm. At the same time, the luminous flux is greatly increased to achieve the detection and calibration of high signal-to-noise ratio (SNR) of the LLL spectrum. In addition, in order to eliminate the phase thermal drift error caused by ambient temperature. Barium metaborate (伪 -BBO3) and lithium niobate LiNbO3 (LiNbO3) crystals are selected for precise combination matching. This key technique utilizes the opposite characteristics of the difference between the birefringence of the two crystals with temperature. The experimental results show that the thermal phase drift error is not more than 0.02 rad. the precision of polarization interferometry spectrometer is improved by these schemes. The calibration and measurement of astronomical light comb and other large astronomical spectrometers are proposed.
【作者单位】：中国科学院国家天文台南京天文光学技术研究所;中国科学院天文光学技术重点实验室;南京理工大学电子工程与光电技术学院;
【基金】：中国科学院天文光学技术重点实验室开放课题基金项目(CAS-KLAOT-KF201402)资助
【分类号】：O433;TH744.1
【正文快照】： 引言干涉成像光谱技术基于光谱线型函数和干涉图相干度函数的傅里叶变换对关系[1]。干涉成像式光谱仪不仅较之色散型光谱仪具有多通道优点、高信噪比的优点(Jacquinot优点),同时其还具有原理简单、体积小、光谱测量实时性好、光谱线性度高、光谱范围宽、分辨率高和抗震性能好

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