| 摘要 |
1,166,922. Lasers. COMMISSARIAT A L'ENERGIE ATOMIQUE. 13 March, 1967 [25 March, 1966], No. 11709/67. Heading H1C. Coherent light generated in a laser resonant cavity is concentrated into a wave packet having a length which is less than the length of the cavity and is then extracted from the cavity. The active medium 9 is initially pumped while cavity reflector 2 is non-parallel to reflector 13. With the reflectors parallel, electro-optical modulator M, consisting of a Pockels cell 12 and a Glan prism 10, is energized with A.C. so that its instant of maximum transmission recurs with a period equal to the time taken for light to travel from the modulator to reflector 2 and back to the modulator. As a result photons emitted from the active medium tend to concentrate in a wave packet which is transmitted by the modulator at the instant of maximum transmission. When this wave packet has formed a D.C. voltage is applied to electrooptical switch C, also consisting of a Pockels cell and Glan prism, to deflect the wave packet out of the cavity. In a second embodiment the modulator and switch are combined in a single unit and in a third embodiment this unit also performs the same function as the rotating prism 2, the cavity being initially give a low Q by applying a D.C. voltage to the electro-optical cell. The prism is in this embodiment replaced by a plane mirror. |
