| 摘要 |
PURPOSE:To obtain the titled device with high vibration resistance by making measuring light and reference light projected from a separating optical system incident on a beam splitter, dividing these incident light rays into two light flux shifted in the horizontal direction to the advancing direction and displacing the beam splitter by a piezo-electric element. CONSTITUTION:Only the optical path of the measuring light can be changed by displacing the beam splitter 11 in the horizontal direction by the piezo-electric element 5. While changing the optical path of the measuring light by the piezo- electric element 5, the light intensity of each point in an interference area is measured by an area sensor 9 and prescribed operation is applied to the measured value to obtain the phase difference between the measuring wave front and the reference wave front, so that the shape of the measuring wave front, i.e. the shape of the shape measuring plane of a substance 10 to be measured, is specified. |
