| 摘要 |
PURPOSE:To obtain a laser capable of performing a laser oscillation and a light amplification by one laser medium by a method wherein the laser is provided with an optical path modifying means to form the optical path of such a laser beam as to be able to lead out to the outside after the laser beam having a plane of polarization modified by a plane-of-polarization modifying means is directed again into the laser medium utilizing the reflection action of a polarizer and is amplified. CONSTITUTION:When a Pockels element control device 7a receives a delay pulse from a central control device 13, a voltage which is applied to a Pockels element 7 is made zero. If so, the action of a laser beam, whose plane of polarization has been modified by 90 deg. by the element 7, is stopped during the time when the voltage is zero. Thereby, a laser beam r0 having a plane of polarization parallel to the plane of the paper when it passes through a polarizer 6 is reflected by a totally reflecting mirror 4 and when the beam r0 is returned to the polarizer 6, it receives the action only of a lambda/4 plate 10 and is turned into a laser beam r1 (whose plane of polarization is vertical to the plane of paper), which is a linearly polarized light having a plane of polarization shifted by 90 deg. to that of the former laser beam. Therefore, this laser beam r1 is reflected by the polarizer 6, goes through a reflecting mirror 8, a beam expander 12, a reflecting mirror 9 and a polarizer 5, is directed into a laser medium 1, is light-amplified by the laser medium 1 to become a strong laser beam r2 and the laser beam r2 is reflected by the polarizer 6 and is led out to the outside. |
