| 摘要 |
PURPOSE:To produce a moire fringe hologram which contains no excessive noise, by providing a device which changes periodically the travelling direction of the light emitted from a light source and an aperture having two holes or a slit having two openings. CONSTITUTION:The light beam generated from a laser 1 is first reflected by a rotary mirror 9 and then passes through an aperture 10 having two holes. This beam is then divided by a beam splitter 3 into subject beams 11 and 11' and reference beams 12 and 12', and beams 11, 11' irradiate a vibrating subject 7. In this case, the revolutions of the mirror 9 are controlled so that the beams pass through the two holes of the aperture 10 when the vibration of the subject 7 is at its peak. As a result, a stroboscope shutter is eliminated. Thus it is possible to produce a moire fringe hologram which contains no excessive noise by one laser. |
