Maru K, Katsumi S, Matsuda R
Department of Electronics and Information Engineering, Kagawa University, 2217-20 Hayashi-cho, Takamatsu, Kagawa 761-0396, Japan.
Rev Sci Instrum. 2017 Apr;88(4):045001. doi: 10.1063/1.4979563.
In this study, we propose and demonstrate a nonmechanical compact probe for cross-sectional velocity measurement based on differential laser Doppler velocimetry. The system introduces a method that combines simultaneous multipoint measurement using spatial encoding and nonmechanical scanning of measurement points, in which spatially encoded measurement points aligned along the transverse direction are scanned in the axial direction by changing the wavelength. The use of a waveguide-type LiNbO phase shifter array for serrodyne frequency shifting is feasible for the system based on fiber optics with an easily handled probe. To miniaturize the probe, a multimode fiber is introduced in the receiving optics and the parameters of the lens system in the transmitting optics are optimized. For the experiment, an eight-channel probe was assembled on an aluminum plate with an 8 cm × 8 cm area size. The experimental results reveal that the cross-sectional two-dimensional velocity distribution was successfully measured using the easily handled compact probe for the first time.
在本研究中，我们提出并演示了一种基于差分激光多普勒测速技术的用于横截面速度测量的非机械紧凑型探头。该系统引入了一种方法，该方法结合了使用空间编码的同步多点测量和测量点的非机械扫描，其中沿横向排列的空间编码测量点通过改变波长在轴向进行扫描。基于具有易于操作探头的光纤系统，使用波导型铌酸锂移相器阵列进行锯齿波频率移相是可行的。为了使探头小型化，在接收光学系统中引入了多模光纤，并优化了发射光学系统中透镜系统的参数。对于实验，在面积尺寸为8 cm×8 cm的铝板上组装了一个八通道探头。实验结果表明，首次使用易于操作的紧凑型探头成功测量了横截面二维速度分布。
