声光频谱仪频率分辨率判断方法研究  

Study on frequency resolution judgment for acousto-optic spectrum analyzer

作　　者：何其锐[1] 李立萍[2] 周鹰[1] 高椿明[1] 

机构地区：[1]电子科技大学光电信息学院,四川成都610054 [2]电子科技大学电子工程学院,四川成都611731

出　　处：《光电子．激光》2014年第10期1865-1869,共5页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金(61379013)资助项目

摘　　要：频率分辨率是声光频谱仪的一个重要指标。声光布拉格器件实际衍射光宽度远大于理论宽度,因此对声光频谱仪频率分辨率的估计需根据实际衍射光的宽度来判断。本文在现有光学测试平台下,对单频信号产生的衍射光,通过高斯函数建立数学模型,利用二分迭代法得到两高斯函数在满足瑞利判据条件下可分辨的最小间距。根据光路系统衍射光偏转距离与对应频率带宽,估计系统频率分辨率与实测系统频率分辨率基本一致。研究结果表明,本文方法能有效估计声光频谱仪的频率分辨率。Frequency resolution is a main parameter of the acousto-optic spectrum analyzer.Because the actual diffraction width of the acousto-optic Bragg device is much larger than the theoretical width,we need to estimate the frequency resolution of the acousto-optic spectrum analyzer by the actual diffraction width.Under the existing optical experimental platform,we establish the mathematical model by the Gaussian function for the diffraction,which is stimulated by one radio frequency（RF）signal.We have solved the two Gaussian function superposition equations by dichotomy,and get the minimum distance which could be distinguished under the Rayleigh criterion condition.According to diffraction deflection distance of the optical system and the corresponding frequency bandwidth,we get the estimated frequency resolution.According to the multiplication property of Fourier transform,we generated the dual-frequency immediate frequency（IF）signal by the signal generator,and measure the frequency resolution of this optical system.The test results show that the estimated frequency resolution and the real frequency resolution of this optic system are basically the same.We can estimate the acousto-optic frequency resolution by this method.

关 键 词：频率分辨率 声光频谱仪 高斯拟合 二分迭代法 

分 类 号：TM935.23[电气工程—电力电子与电力传动]