声光光谱仪的光谱及辐射标定方法  

Spectral and Radiometric Calibration Methods for Acousto-Optic Spectrometer

作　　者：成驰 赵慧洁[1,2,3,4] 郭琦 李然[3] Cheng Chi;Zhao Huijie;Guo Qi;Li Ran(School of Instrumentation and Opto-Electronic Engineering,Beihang University,Beijing 100191,China;Qingdao Research Institute of Beihang University,Qingdao 266104,Shandong,China;Institute of Artificial Intelligence,Beihang University,Beijing 100191,China;Aerospace Optical-Microwave Integrated Precision Intelligent Sensing,Key Laboratory of Ministry of Industry and Information Technology,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100191 [2]北京航空航天大学青岛研究院,山东青岛266104 [3]北京航空航天大学人工智能研究院,北京100191 [4]北京航空航天大学“空天光学-微波一体化精准智能感知”工业和信息化部重点实验室,北京100191

出　　处：《光学学报》2024年第9期274-283,共10页Acta Optica Sinica

摘　　要：基于声光可调谐滤波器(AOTF)的红外光谱仪须在宽温度范围内具备光谱响应稳定性,以保证光谱数据精度。然而,随环境温度变化,声光光谱仪存在光谱漂移和系统辐射响应漂移,造成光谱数据偏差。现有声光光谱仪辐射定标研究虽然考虑了辐射响应受温度的影响,但并未在辐射定标前修正光谱漂移,导致辐射定标结果不准确。本文提出了一种修正温度影响的光谱及辐射标定方法。首先,建立了引入温度变量的AOTF器件调谐模型,在光谱定标中修正温度造成的光谱漂移,实现了变温辐射定标过程中的波长追踪;然后再求得含温度变量的光谱辐射定标系数,完成辐射定标。依托实验室搭建的中波红外AOTF光谱成像温度修正标定验证系统,在-30~50℃温度区间验证了标定方法的有效性。低温-30℃处的平均驱动频率偏差从41.1 kHz降低至0.29 kHz,修正后光谱辐射量与理论值偏差在低温区间显著降低。Objective Imaging spectrometers based on acousto-optic tunable filters(AOTFs)are widely recognized for their rapid tuning,reliability,repeatability,and ability to change spectral channels with ease.These instruments have been extensively studied in space remote sensing and reconnaissance.Meanwhile,the spectrometers should be capable of functioning accurately over a broad temperature range to deliver precise spectral information across various operating environments.However,the spectral data accuracy is compromised by ambient temperature fluctuations,which affects the AOTF’s spectral tuning and the spectrometer’s response to radiation.The tuning relationship shift is predominantly the result of refractive index changes in the acousto-optic crystal and the velocity of acoustic waves as temperature varies,altering the acousto-optic interaction within the crystal.Similarly,the spectrometer’s radiation response drifts due to alterations in the AOTF’s diffraction efficiency and temperature-dependent changes in the performance of both electronic and optical components.Although previous studies have taken account of the temperature drift in radiation response during the radiometric calibration,it is necessary to first ensure the spectral wavelength stability in the output images,and otherwise,radiometric calibration cannot be achieved.Therefore,implementing temperature corrections during spectral calibration is essential to prevent wavelength deviations in the output images during temperature shifts,which would result in erroneous radiometric calibration.Methods We propose a spectral and radiometric calibration method for correcting temperature effects.Firstly,an AOTF tuning model that incorporates a temperature variable is built.Within this model,the relationship between the drive frequency and the optical wavelength,acoustic wave velocity,refractive index,angle of incidence,and acoustic cut angle is derived.The effect of acoustic wave velocity on the drive frequency is considered independently,and a temperature

关 键 词：中波红外光谱仪 声光可调谐滤波器 温度漂移 辐射定标 

分 类 号：TP73[自动化与计算机技术—检测技术与自动化装置]