Development of an asymetric optical resonator for the monochromatic gamma-ray source

激光康普顿散射（LCS）产生的高强度单色伽玛射线源是核共振荧光无损检测系统中一种非常有用的探针。通过进一步研制纯单色LCS源，提高了测量系统的精度。由于锁模短脉冲激光器的能量扩散限制了LCS光源的单色性，因此应采用超窄带宽激光器代替短脉冲激光器。本研究开发了一种纯单色LCS光源的增强腔。提出了一种非对称共聚焦法布里-珀罗光谐振腔作为纯单色LCS光源的增强腔。研究结果清楚地表明，非对称光学谐振腔的反射镜应为抛物面反射镜。利用光线追踪法分析了反射镜畸变和不对准的影响。

A high intensity monochromatic gamma-ray source from the laser Compton scattering (LCS) is a very useful probe for a nondestructive assay system by means of nuclear resonance fluorescence. The accuracy improvement of the measurement system is attained by further developing a pure monochromatic LCS source. Since, the monochromaticity of the LCS light source is restricted by the energy spread of the mode-locked short pulse laser, an ultra-narrow band width laser should be used for instead of the short pulse laser. An enhancement cavity for the pure monochromatic LCS source has been developed in this study. An asymmetric confocal Fabry-Perot optical resonator was proposed as an enhancement cavity of the pure monochromatic LCS source. In the result of the study, it was shown clearly that the mirrors of the asymmetric optical resonator should be parabolic mirrors. The influences due to the distortion and the misalignment of the mirrors were evaluated by a raytrace method.