| 摘要 |
PURPOSE:To stabilize the divergence angle of beams of tansmission laser beam by introducing part of the laser beam from a laser oscillator to a beam divergence detector, and controlling the divergence angle of beams of the transmission optical system based on the output of this detector. CONSTITUTION:The laser beam outputted from the output mirror 6 of a laser oscillator enters a beam splitter 9, by which part thereof is reflected and enters a beam divergence detector 10. The greater part of the beam transmits through said detector and enters a transmission optical system 11. The system 11 is for example a zoom lens of which the magnification is continuously variable, and when the change quantity signal for the magnification of the zoom lens necessary for setting the transmission beam divergence angle from the detector 10 at a prescribed value is sent to a servomechanism 12, the servomechanism 12 drives the variable magnification mechanism of the zoom lens according to the signal from the detector 10, thereby changing the magnification of the zoom lens. |
