Dual-modulation fiber Fabry-Perot interferometer with double reflection for slowly-varying displacements

This Letter describes a dual-amplitude modulation technique incorporated into a double reflection extrinsic-type fiber Fabry-Perot interferometer to measure periodic, nonperiodic as well as quasi-static displacements. The modulation scheme simultaneously maintains the interference signal pair in quadrature and provides a reference signal for displacements inferior to a quarter of the source wavelength. The control and phase demodulation of the interferometer carried out via software enable quasi-real-time measurement and facilitates sensor alignment. The sensor system can be exploited in the low frequency range from 10(-3) to ～500 Hz and has a resolution better than 2.2 nm, targeting applications in geophysics.     

“Noninverted” interference fringes upon light reflection from a Fabry-Perot interferometer with an asymmetric diffraction mirror

This paper describes the calculation, fabrication, and experimental investigation of a reflection two-mirror interferometer whose front mirror is asymmetric in reflection and made as a thin-layer diffraction metal structure (Al, Ag) in combination with a dielectric coating (MgF₂, ZnS). In reflection, this interferometer creates in the zero diffraction order a transmission-like pattern similar to that produced by an ordinary Fabry-Perot interferometer operating in transmitted light.     

Jamin Fabry-Perot interferometer

A novel type of interferometer was designed and tested experimentally. It combines the advantages of the spatial path separation used in the two-wave polarized Jamin interferometer and the high sensitivity that characterizes the multiwave Fabry-Perot interferometer. Furthermore, when it is sandwiched between crossed polarizers it shows a sensitivity to intracavity anisotropies that is proportional to the square of the Fabry-Perot interferometer's finesse.     

基于双F-P干涉仪的多普勒测风激光雷达的性能分析

 自行研制了一台基于双边缘技术的多普勒激光雷达,用于测量对流层大气风场。该雷达采用具有高光谱分辨率的双Fabry-Perot干涉仪来检测气溶胶后向散射的多普勒频移量。给出了多普勒测风激光雷达的结构和参数。利用干涉仪参数讨论了雷达系统的测量精度。实验测定了双干涉仪的频谱曲线。通过计算和分析,由测量的干涉仪频谱曲线的的标准偏差引起的系统测量误差为0.5 m/s。系统的测量误差随着测量的高度和所测速度的增加在增大,在高度10 km测量50 m/s的风速时系统的测量误差小于2 m/s。     

基于双F-P干涉仪的多普勒测风激光雷达的性能分析

自行研制了一台基于双边缘技术的多普勒激光雷达,用于测量对流层大气风场。该雷达采用具有高光谱分辨率的双Fabry-Perot干涉仪来检测气溶胶后向散射的多普勒频移量。给出了多普勒测风激光雷达的结构和参数。利用干涉仪参数讨论了雷达系统的测量精度。实验测定了双干涉仪的频谱曲线。通过计算和分析,由测量的干涉仪频谱曲线的的标准偏差引起的系统测量误差为0.5 m/s。系统的测量误差随着测量的高度和所测速度的增加在增大,在高度10 km测量50 m/s的风速时系统的测量误差小于2 m/s。     

Theory of the Fabry-Perot interferometer with nonparallel reflectors

Taking into account the wave structure of the light beam, determined by diffraction theory, we consider the harmful effect of the inclination of the mirrors of a Fabry-Perot interferometer when fringes of equal inclination are being observed. It is found that the contrast and resolution of the fringes of equal inclination are reduced as the angle of the wedge so formed is increased, and the interferometer (resonator) completely loses its high-resolution capability (Q-factor) when the mirrors deviate from parallelism by an angle equal to half the diffraction angle at its aperture. The advantages of stopping down both the incoming and outgoing beams in improving the contrast and increasing the resolution of the fringes of equal inclination are pointed out.The author thanks Professor F. A. Korolev for his interest.     

High contrast multi-pass Fabry-Perot interferometer

A technique for improving the contrast ratio of a Fabry-Perot spectrometer is presented. Using triplepasses of radiation through a mesh-reflector Fabry-Perot it is shown how the contrast ratio may be improved by orders of magnitude. Experimental verification has been demonstrated and the application of the technique to specific cases of interest discussed briefly. Overall improvement in finesse as well as contrast ratio has been achieved with only small loss in transmission.     

Instability of Fabry-Perot interferometer with a multilayered paramagnetic filling

The results of the analysis of the stability of stationary solutions of wave equations discribing a behavior of the nonlinear Fabry-Perot interferometer with a saturated paramagnetic filling are presented in this paper. The cases when paramagnetic medium is characterized by a homogeneously and nonhomogeneously broadened line of the magnetic resonance have been considered. Areas of unstable behavior of these characteristics of the resonance structure have been found.     

芯内双微孔复合腔结构的光纤法布里-珀罗传感器研究

提出了一种基于芯内双微孔复合结构的全光纤干涉传感器结构,建立了传感器反射光谱的理论模型,给出了反射光谱强度与微孔长度、孔内介质折射率、微孔端面反射与损耗系数以及光纤的特性参数间的关系,并模拟了传感器光谱对温度和折射率变化的响应特性.利用193 nm准分子激光器,在普通单模光纤上加工制作了具有复合腔结构的全光纤多参量传感器,进行了传感实验研究.结果表明,该传感器具有优于99%的温度、折射率线性响应度,对应两套温度和折射率灵敏度分别为-0.172 nm/℃,1050.700 nm/RIU和0.004 nm/℃,48.775 nm/RIU,不仅能够实现温度、折射率以及它们的区分测量,还能够应用于气体压力的测量,测量精度可达0.3 kPa.     

扫描式法布里-珀罗干涉仪测量高空大气风速

为测量中低纬度地区250km高空大气风速，采用扫描式法布里 珀罗干涉仪记录250km高度附近的OI630nm气辉辐射谱线的干涉图像。通过对观测图像分析处理，用高斯函数匹配干涉条纹强度分布以确定干涉条纹强度中心的精确位置，进而求出谱线的多普勒频移，反演出经向和纬向风速。经过理论推导，求出F P腔间距的漂移量对风速的影响，对反演风速进行修正。由风速随时间变化曲线得到在观测期间，经向风朝南，大小在4～67m/s间变化；纬向风朝东，大小在20～100m/s间变化，最小风速误差约为6m/s。     

Transformation of the amplitude profiles of coherent light beams in a nonlinear photorefractive Fabry-Perot interferometer

The transformations of the transverse profiles of laser beams in a nonlinear Fabry-Perot interferometer based on lithium niobate crystals with a surface layer doped with a combination of photorefractive impurities (iron and copper ions) have been experimentally investigated. It is demonstrated that the distribution of transmitted beam intensity significantly changes for a few seconds at milliwatt beam powers.     

法布里-珀罗气辉干涉成像仪的大气温度测量原理

讨论了法布里-珀罗干涉成像仪（FPI）对夜气辉的系统响应,更为明确地描述了建立该干涉系统数学模型的方法和结果。在此基础上阐述了利用FPI对热层大气温度进行测量的原理,并且通过分析稳频He-Ne激光器的干涉图对系统的传输函数进行了求解,对不同波长下系统传输函数的转换进行了讨论。干涉图的分析结果表明：该解析模型以及波长转换方法能够很好地表示干涉成像系统。另外对系统传输函数在实际气辉测量中的应用、系统的温度漂移以及误差估计也进行了简要讨论。     

Limiting instrumental function of the Fabry-Perot interferometer

Journal of Applied Spectroscopy -