光梳多波长绝对测距的波长选择及非模糊度量程分析  

Wavelength Selection and Non-Ambiguity Range Analysis for OpticalComb-Referenced Multi-Wavelength Absolute Distance Measurement

作　　者：王国超[1] 魏春华[1] 颜树华[1] 

机构地区：[1]国防科学技术大学机电工程与自动化学院,湖南长沙410073

出　　处：《光学学报》2014年第4期111-117,共7页Acta Optica Sinica

基　　金：国家自然科学基金(51275523);湖南省研究生科研创新项目(CX2012B015);国防科学技术大学优秀研究生创新项目(B120305)

摘　　要：飞秒光学频率梳作为精密光学频率标尺,可以用来产生频率稳定度极高的单波长连续激光,利用其多个梳模制备理想的多波长光源用于绝对距离测量具有测量速度快、实时性强、非模糊度量程大、精度高等优点。以多波长测距的基本理论和光梳高频率稳定度为基础,提出了二次合成波长的方法,不仅扩展了非模糊度量程,同时为干涉信号的多波长解调创造了足够的波长间隔条件。结合光梳的波长特点,分析了基于光梳的多波长选择与非模糊度量程的关系,并阐述了具体的选择步骤及波长组合结构。利用小数重合解调算法,在0.01的小数相位测量精度条件下,仿真验证了四波长干涉测距的非模糊度量程为35.636mm,五波长干涉系统可以达到几百毫米的非模糊度量程,后者相对分辨力的动态量程达到109量级。As a precise optical frequency ruler, femtosecond optical frequency comb can be used to generate continuous-wave laser with ultrahigh frequency stability. Absolute distance measurement by multi-wavelength interferometry, making use of multiple wavelengths referenced to comb modes, has advantages of fast measuring speed, real time, large non-ambiguity range and high precision. Based on the theory of multi-wavelength interferometry and high frequency stability of optical comb, the second-order synthetic wavelength method is proposed to extend the non-ambiguity range and keep an enough wavelength gap for the wavelength demultiplexing of interference signals. Combined with characteristics of wavelengths in the optical comb, relationship between non-ambiguity range and wavelengths is analyzed, and selection procedure is elaborated. Simulation is performed with a fractional coincidence demodulation algorithm. The result shows that four wavelengths interferometry can achieve a non-ambiguity range of 35.636 mm with fractional phase accuracy of 0.01, and in the case of five wavelengths that range can be up to several hundred millimeters. The latter range corresponds to a dynamic range of 109 level, relative to measurement resolution.

关 键 词：测量 绝对距离测量 多波长干涉 非模糊度量程 光学频率梳 合成波长 

分 类 号：TN249[电子电信—物理电子学]