| 摘要 |
PURPOSE:To reduce the measuring time with the method decreasing the signal distortion, by adding the interference signal values at the two locations apart by equal distance from the maximum position of the interference signal with the position of the drive mirror of the Michelson interference meter. CONSTITUTION:The infrared rays from the output light source L are emitted to the silicon wafer 10 via the reflection mirrors M1-M3, and the reflected light is led to the Michelson interference meter 1 via the reflection mirrors M4-M6. The interference light is fed to the photoelectric converter DET via the semi-transparent mirror HM, fixed mirror FM, and driven mirror DM and it is converted into electric signal as analog quantity. It is converted into digital signal at the analog digital convension circuit 2 and inputted to the computer 5 via the interface circuit 3. It is stored in the memory unit 52 via the operation and the control unit 51, and the result of operation is displayed 6. Maximum value is detected with the scanning of the memory address of the memory unit 52, the memory information before and after being equal distance from the value are added. This addition produces the signal in which distortion is substantially eliminated. |
