| 摘要 |
PURPOSE:To visualize the acoustic field without disturbing it, by dividing a laser light into a reference light and an object illuminating light, which is passed through a lens, a diffusing matter and an object to be measured on the acoustic field to form an image of laser speckles on a screen by way of the reference light. CONSTITUTION:Light from a laser light source 1 is divided into a reference light 3 and a object illuminating light 4 with a beam splitter 2. The reference light 3 is incident to a dry plate 7 via a reflecting mirror 5 and a lens 6. The object illuminating light 4 is turned to a diffused light 4' with a lens 9 via a reflector 8 and reflected on the diffusing matter 10 to be incident into the dry plate 7 through an object 11 to be measured on the sound field. The reference light 3' and the diffused light 4' incident into the dry plate 7 interfer with each other to form a laser speckle. Thus, the acoustic field being generated through an oscillator 12, audio amplifier 13 and a speaker 14, and the other without it. |
