宽波段傅里叶变换太阳光谱仪等光程差采样系统设计  

Design of Equal Optical Path Difference Sampling System for Wide Band Fourier Transform Solar Spectrometer

作　　者：朱晓明[1,2,3] 白先勇 林佳本[1,2] 段帷 邓元勇[1,2] 冯志伟[1,2] 张志勇[1,2] 杨潇[1,2] 郭思璠[1,2,3] 白阳[1,2,3] ZHU Xiao-ming;BAI Xian-yong;LIN Jia-ben;DUAN Wei;DENG Yuan-yong;FENG Zhi-wei;ZHANG Zhi-yong;YANG Xiao;GUO Si-fan;BAI Yang(National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101;Key Laboratory of Solar Activity,Chinese Academy of Sciences,Beijing 100101;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院国家天文台,北京100101 [2]中国科学院太阳活动重点实验室,北京100101 [3]中国科学院大学,北京100049

出　　处：《天文学报》2023年第2期11-20,共10页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(11873062、12003051、11973061);国家基金委重大科研仪器研制项目(11427901)资助。

摘　　要：太阳成像光谱探测是诊断太阳大气磁场和热力学参数的主要手段.傅里叶变换太阳光谱仪(Fourier Transform Solar Spectrometer, FTSS)具有宽波段的优势,是当前中红外高分辨率太阳光谱探测的最佳选择.FTSS通过采集目标辐射等光程差干涉图,反演获得光谱图,等光程差采样的间隔决定了反演光谱波长范围.因此从FTSS宽波段光谱观测对不同等光程差采样间隔需求出发,基于现场可编程门阵列(Field Programmable Gate Array, FPGA)技术,采用全数字分频、倍频方案,设计了一套宽波段FTSS等光程差采样系统.采用分布式余数补偿方法,有效解决了在参考激光干涉信号倍频过程中,输出采样信号在输出信号周期间误差累积问题,并降低了输出采样信号的误差及非均匀性;经功能仿真及实验测试,系统在200 Hz–50 kHz频率范围内,频率误差δ <0.04%,可有效满足FTSS的300 nm–25μm宽波段的光谱观测数据采集需求,为后续可见和红外波段FTSS的研制奠定了技术基础.Solar imaging spectral detection is a main method for diagnosing the magnetic field and thermodynamic parameters of the solar atmosphere.The Fourier Transform Solar Spectrometer(FTSS)has the advantage of wide band and is the best choice for the current mid-infrared high-resolution solar spectrum detection.FTSS acquires spectra through the inversion of the observed interferogram from the target radiation,and the sampling interval of the optical path difference determines the wavelength range of the inversion spectrum.Therefore,from the requirement of tunable optical path difference interval for FTSS’s broadband spectral observations,we designed a sampling system with fully digital frequency division and multiplication scheme based on FPGA(Field Programmable Gate Array)technology.The distributed remainder compensation method is adopted to effectively solve the problem of error accumulation in the process of frequency multiplying of the reference laser signal,and the non-uniformity of the output sampling signal is also reduced.After simulations and experimental measurements,the system frequency erroris less than 0.04%,in the frequency range of 200 Hz–50 kHz,which meets the FTSS’s broadband spectral observation requirements of 300 nm–25m.This study has laid a solid technical foundation for the development of FTSS in visible and infrared bands.

关 键 词：太阳:磁场 技术:傅里叶变换光谱仪 数字分频 数字倍频 

分 类 号：P111[天文地球—天文学]