| 摘要 |
1,139,177. Lasers. PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd. 6 Sept., 1966 [9 Sept., 1965], No. 39810/66. Heading H1C. A gas laser is located in an unvarying first magnetic field which is transverse of the resonator axis and also in a pulsed second magnetic field which is longitudinal of this axis, the first magnetic field polarizing the output in a plane which can occupy either one of two stable positions located symmetrically with respect to the transverse field, while the direction of the second field determines in which of these positions the output is polarized. By applying the second field for a short duration in the opposite sense, the polarization plane is switched from one stable position to the other. A pulse code modulated output, e.g. delta modulation, is produced by appropriate control of the second magnetic field. A modulator is described, Fig. 1, in which a ducted quartz block 1 is sealed by quartz blocks 3, 4 provided with dichroic mirrors 5, 6, the duct 2 being filled with helium containing 5% of neon. A D.C. gas discharge is produced between electrodes 7 and 8 and the first and second magnetic fields are established by coils 11 and 14 respectively. |
