| 摘要 |
PURPOSE:To enable real time detection only with a main body by using a Fabry- Perot interferometer which makes repeated reflections between flat plates arranged in parallel to each other ad having predetermined reflecting films on respective end faces, with an elastic body interposed therebetween. CONSTITUTION:Flat plates 2, 4 having light permeability with predetermined reflecting films 2r, 4r coated on their respective end faces are arranged on a measuring object 1. At this time, the reflecting films 2r, 4r are set parallel to each other with an elastic film 3 interposed therebetween. The elastic film 3 and flat plates 2, 4 are bonded securely, thereby forming a Fabry-Perot interferometer as a whole. The thickness of the elastic film 3 is adjusted to set the distance between the reflecting films 2r and 4r to be the optimum interfering distance. The oscillation of the measuring object 1 is received by a spring- measure system constituted by the elastic body 3 and flat plate 4 working as a measure. The elastic body 3 shrinks due to the force brought about at the measure, changing the interfering distance. Accordingly, the intensity of light returning to the flat plate 4 is changed, from which the oscillating amount is known. The oscillating state becomes visible real time through the brightness change accompanying the intensity change. |
