| 摘要 |
PURPOSE:To enable vibration of an object to be measured to be detected constantly and stably in a vibration detection method for detecting the vibration of the object to be measured based on a vibration component of interference light obtained by superposing measurement light from the object to be measured and reference light. CONSTITUTION:Light from a laser light source 1 is reflected by an object 3 to be measured and a reflection mirror 5, thus resulting in interference. Then, the interference light is divided by beam splitters 7 and 8 and phases of lights 9 and 11 are changed by pi/2 with respect to light 10 which becomes a reference, thus enabling a plurality of interference signals with a different phase to be generated and an interference signal where a vibration component is maximized is selected from a plurality of interference signals and a vibration of the object 3 to be measured to be detected. |
