| 摘要 |
PURPOSE:To eliminate the disturbance from the outside by emitting two light beams having different wavelengths and polarization components from two lasers in the same transmitting and receiving telescopes at the same time, and receiving them with the polarization components while they are separated from each other. CONSTITUTION:The laser light, which has a first polarization component and wavelength and is emitted from a first laser, is transmitted through a transparent body 3. The laser light, which has a second polarization component and wavelength and is emitted from a second laser, is reflected by the transparent body 3. Said transparent body 3 is arranged on a laser light paths of the first and second lasers. In this case, the first and second lasers 1 and 2 and the transparent body 3 are so arranged that the laser light beams emitted through the transparent body 3 pass the same optical path. On the same optical returning path, along which emitted light beams pass a space to be measured and return, transparent bodies 4 and 5, which transmit a laser beam having one polarization component and reflect the other laser beam having the other polarization component, are provided. The transmitted light and the reflected light are detected by detectors D1 and D2, respectively, and the detected outputs are compared. |
