| 摘要 |
PURPOSE:To accurately measure the diameter and expanding angle of a laser beam having a large aperture and a narrow expanding angle by such an arrangement wherein a reflecting plate having straight edges is caused to move and scan for a laser beam to be measured and the intensity of the reflected light of the laser beam is remotely deteced by means of a photoelectric detector. CONSTITUTION:A laser beam 23 to be measured radiated from the transmission optical system 22 of a laser radar device 20 is gradually covered and reflected by the scanning of a reflecting plate 24. The reflecting plate 24 is a diffusion reflecting plate as it is required to have uniform reflection characteristics. The length of scanning of the reflecting plate 24 can be measured by a graduated scale 26 installed to a reflection supporting base 25. Every time when the reflecting plate 24 is moved at a proper interval, the intensity of a reflected light 27 detected by a detector 29 is read out and recorded by a display unit 30. The beam diameter of the laser beam to be measured 23 is calculated from recorded data. The expansion angle of the laser beam 23 can be obtained by measuring beam diameter at more than 2 different points. By this, a very narrow expansion angle can be measured. |
