Development and application of the pulsed-laser super optical cavity

本研究的目的如下：(1)建立脉冲激光法布里-珀罗光腔技术。(2)改进激光线监测仪，更好地了解KEK-ATF光束动力学。特别是利用高斯光束的高模提高激光线的空间分辨率。(3)对紧凑、明亮的x射线源进行先导实验。在研究期间，我们获得了以下结果。针对(1)点，我们在Fabry-Perot光腔中注入了一个锁模脉冲激光器，获得了630的功率增益。通过反馈系统稳定地维持谐振状态。腔内平均功率为2。4KW，对应的峰值功率约为1mw。目前实现的梁腰为178微米。虽然还有进一步改进的空间，但我们对这些结果感到满意。在目标(2)上，我们建立了稳定产生高模高斯光束的途径。我们研究了它们的特点，证实它们都符合理论预期。在TEM01模式下，我们测量了ATF阻尼环（KEK）的电子束尺寸。在第(3)点上，我们已经开始通过将我们的腔置于rf枪直线加速器产生的电子束中来开发x射线源。该腔体目前已安装在光束直线x射线探测器中，对x射线源的详细研究正在进行中。

The aims of this research are as follows : (1) To establish techniques of Fabry-Perot optical cavity using pulsed laser. (2) To improve laser wire monitors and to understand better KEK-ATF beam dynamics with it. In particular, to improve the laser wire spatial resolution using higher-modes of Gauss beam. (3) To perform pilot experiment toward a compact, bright X-ray source. During the research period, we have obtained the following results. Concerning to the point (1), we injected a mode-locked pulse laser into our Fabry-Perot optical cavity, and achieved a power gain of 630. The resonance condition was stably maintained by a feedback system. The averaged power in the cavity was 2. 4KW, corresponding to a peak power of about 1 MW. The beam waist achieved so far was 178 micro-meter. Although there is still room to improve further, we are satisfied with these results. On the goal (2), we established the way to stably produce higher-mode gauss beams. We studied their characteristics and confirmed that all agree well with the theoretical expectations. With the laser wire operating in the TEM01 mode, we measured the electron beam sizes of the ATF damping ring (KEK). On the point (3), we have begun developing an X-ray source by putting our cavity in an electron beam produced by a RF-gun linac. The cavity is now installed in the beam linac X-ray detection and detailed studies of the X-ray source are now under way.