| 摘要 |
PURPOSE:To discriminate the direction of movement of fine particles by comparatively simple constitution in a laser-velocity measuring device, in which two laser beams are crossed and particle velocity is detected from the scattered light of the fine particles passing through a cross region. CONSTITUTION:The laser beams of a semiconductor laser 1 are divided by a beam splitter 2, and focussed at one point by a condenser lens 3, Scattered light passing through an interference fringe formed in a cross region 4 is focussed by a condenser lens 5, and received by a photodiode 6. A two-piece type photodiode is used as the photodiode 6. When an output is obtained from both two regions of the photodiode 6, the direction is discriminated on the basis of the order of light reception. |
