| 摘要 |
PURPOSE:To make the titled device compact by sending focused light flux divided by a half mirror to two plane mirrors arranged so as to be intersected rectangularly and obliquely with the optical axis and displacing one plane mirror by a piezo-electric element to change the optical path. CONSTITUTION:Light from a laser light source 1 is irradiaged to a substance 10 to be measured through colimate lenses L1, L2, a beam splitter 112 and a lens L3 and the reflected light is divided into two light flux consisting of measuring light and reference light by a beam splitter 8 through the lens L3, the beam splitter 112 and a condenser L5. One of these light flux is condensed on a plane mirror 11, the other is focused on a plane mirror 12 and the light transmitted through the plane mirror 11 reaches an area sensor 9 through an image formation lens L4. The plane mirror 12 is inclined by a fine angle theta from the optical axis of the incident light and the reflected light reaches the area sensor 9 with the inclination of 2theta. Since the plane mirror 11 is displaced by a piezo- electric element 5 to change the optical path, the light intensity of each point in an interference area is measured by the area sensor 9 while changing the optical path and prescribed operation is executed. |
