CO_2/CO slab laser excited by high frequency

研制了一台电极尺寸为5×60 cm~2的CO_2板条激光器，激励功率分别为80 MHz、100 MHz和125 MHz。CO_2/N_2/He=1/1/8。获得的最大功率为180-200W。在20ﾟC下，5微米CO激光器也与相同方案的CO_2板条激光器振荡。两个板条激光器耦合在一起，电极尺寸为3×16 cm^2.2。磁场对板条激光器的影响。当激光以较高的频率激励时，间隙长度可以变窄，因为Seath的深度与激励频率成反比。因此，频率越高，功率/cm2越高，但频率越低，如13.5 MHz或27 MHz，越容易操作，成本也越低。当磁场垂直于电流作用于板条激光器等离子体时，电子的路径发生弯曲，高频时的间隙变窄。对这种影响进行了理论分析，并进行了0-400高斯磁场下的实验。3.提出了两种新型的星形耦合板条激光器非稳腔。其中非稳腔的输出被平面镜反射回来，功率从凹面镜中心的光圈耦合出来。在其中的另一个凸镜的中心是平坦的，以构成一个稳定的谐振腔。对它们进行了理论分析，证明了星形耦合板条激光器的有效性。

A CO_2 slab laser was developed, of which size of electrodes are 5x60cm^2, excited by 80,100, and 125MHz RF power. The gas content is CO_2/N_2/He=1/1/8. The maximum power obtained are 180-200W.5mum CO laser also oscillated with the same scheme of CO_2 slab laser at 20ﾟC.The two slab lasers are coupled, of which sizes of electrodes are 3x16cm^2.2.The effect of magnetic field on the slab laser.The cooling is more effective for the narrower gap length in the slab laser. The gap length can be narrower when the laser is excited with the higher frequency, because the depth of the seath is inversely proportional to the excited frequency. So, the higher frequency is preferable for the higher power/cm^2, but the lower frequency such as 13.5MHz or 27MHz are easier to handle and cheaper.When the magnetic field is applied to the plasma of slab laser, perpendicularly to the current, the path of the electron is bent and the gap length can be narrower for the higher frequency.This effect has been theoretically analyzed and the experiment with 0-400 Gauss magnetic field is going on.3.The two types of new unstable resonators are proposed for the star-coupled slab lasers. In one which the output from the unstable resonator is reflected back by the flat mirror, and the power is coupled out from the aperture at the center of the concave mirror. In other of which the center of the convex mirror in flat, to constitute a stable resonator there. They are theoretically analyzed and the effectiveness become clear for the star-coupled slab lasers.