| 摘要 |
PURPOSE:To enable detection of oscillation without intricate arithmetic processing by detecting the movement of a speckle pattern with a one-dimensional array type photodetector and detecting the movement of the peak in the distribution of the light intensity of an array detector. CONSTITUTION:The diode address of an array type photodetector 1 in which photodiodes are arrayed in one row advances one by one upon receiving of the pulse from a controller 6 and the photodiode emits an output. The signal digitized by an A/D converter 3 is stored in a digital arithmetic device 4000. The photodetector 1 can be rotated around the incident direction of light by means of a motor control device 8 and a motor 7 so that the oscillating direction of a speckle pattern and the direction of the diode array of the array photodetector are matched. There are many luminous spots in the speckle pattern. When one of the luminous spots is detected by the photodetector 1 and the direction of the diode array is matched with the oscillating direction, the light falls to the part of the length twice the amplitude on the array. |
