| 摘要 |
PURPOSE:To make possible the measurement of fine particles having diameters of several mum or below by dividing pulse laser light to the 1st-3rd luminous fluxes by a beam splitter. CONSTITUTION:A laser device 1, the beam splitters 5, 25, 28, a photographic dry plate 9 for holography and particle groups 13 to be measured, etc. are provided. The pulse laser light generated by the device 1 is conducted to the 1st splitter 5 by which the laser light is divided to the two luminous fluxes. One thereof is passed through a diffusion plate 12 then through the 2nd splitter 28 and is projected to the particle groups 13. The 1st illuminating light thereof arrives as the 1st object light at the dry plate 9. The other of the laser light is conducted to the 3rd splitter 25 and arrives as the 1st reference light at the dry plate 9. The difference in the optical path length between the 1st object light and the 1st reference light is made smaller than the coherence distance of the laser light so that said object light and reference light induce interference on the dry plate 9. The optical path difference between the 2nd reference light from the spliter 28 and the object light up to the dry plate 9 is made larger than the coherence distance of the laser light by which the simultaneous exposure of the 1st and 2nd reference light and the object light is made possible. |
