光纤耦合自混合二极管激光多普勒测速仪：水和血流中的技术要点及流速剖面扰动

Fiber-coupled self-mixing diode-laser Doppler velocimeter: technical aspects and flow velocity profile disturbances in water and blood flows.

作者信息

Koelink M H, de Mul F F, Weijers A L, Greve J, Graaff R, Dassel A C, Aarnoudse J G

出版信息

Appl Opt. 1994 Aug 20;33(24):5628-41. doi: 10.1364/AO.33.005628.

DOI:10.1364/AO.33.005628

PMID:20935962

Abstract

The effects of disturbances of the flow pattern in front of the fiber facet of a fiber-coupled self-mixing diode-laser Doppler velocimeter system are investigated. This was done by comparing measurements and calculations of the Doppler frequency spectrum with the expected values. The calculated Doppler spectrum was obtained from the calculation of light scattered (with or without Doppler shift) by the moving particles in front of the fiber facet. The velocity profile of the particles was calculated with a finite-element method. Measurements were done with water (with polystyrene spheres) and whole blood as the samples. Good agreement between measurements and calculations were obtained. The velocimeter was modeled as a five-mirror setup. The reflectivity of the fiber facet closest to the laser turns out to have the most influence on the sensitivity and stability of the laser. Direct reflection of unwanted light back into the laser cavity was avoided by placing a glass plate in front of the fiber. Design consi ations are presented.

摘要

研究了光纤耦合自混合二极管激光多普勒测速系统中光纤端面之前流型扰动的影响。通过将多普勒频谱的测量值和计算值与预期值进行比较来完成此项研究。计算得到的多普勒频谱是通过对光纤端面之前移动粒子散射的光（有或无多普勒频移）进行计算而获得的。粒子的速度分布采用有限元方法进行计算。使用水（含聚苯乙烯球体）和全血作为样本进行测量。测量值与计算值之间取得了良好的一致性。该测速仪被建模为五镜装置。结果表明，最靠近激光器的光纤端面的反射率对激光器的灵敏度和稳定性影响最大。通过在光纤前面放置一块玻璃板，避免了不需要的光直接反射回激光腔。文中给出了设计考虑因素。