【摘要】 高能化学氧碘激光(COIL)激光近场存在着大量的高频光,这部分光会对光束质量及强光通道附近的系统造成严重的危害,因此需要研究这些高频光在近场的传输规律。分析了各种不同的高频光的产生机理和特性,其中输出镜的衍射和高阶模对高频光的贡献最大,因此是主要研究对象。通过在光学通道内设置多个测试光阑测量了不同位置的能量,并根据该位置的空间角计算出高频光角谱。采用了三种不同的研究方法分别计算在不同出光时间下的角谱特征,得到了较一致的结果。研究结果表明高频光的角谱越往通道后端数值越大,当光束质量恶化时角谱值增大,通道内的能量损失增加。根据角谱曲线可以计算出每个防护光阑上的功率和能量,这为高能COIL激光系统热管理技术奠定了坚实的基础。更多还原

【Abstract】 Much high frequent light exist in the near-field of the high energy chemical oxygen iodine laser(COIL), which cause serious harm to beam quality and system near the high power beam tune.So it is necessary to study the propagation laws of the high frequency light.The generating mechanism and characteristics of different high frequent light are analyzed.Since the diffraction of cavity mirror and higher-order modes contribute to most of the high frequent light,they are main objects of the study.The energies of different positions are measured by the measurement diaphragm set in the beam tune.The angular power spectra of the high frequent light are calculated according to the corresponding space angles on the diaphragm.The angular power spectrum curves changing with the duration are analyzed by three different methods,and the accordant results are got.The research results show that the angular power spectrum in the front is bigger than that in the back,and the angular power spectrum increases with the deterioration of beam quality,and in the same time,the energy loss may enhance,too.The power and energy on each defending diaphragm can be calculated with the angular power spectra,which lays a good foundation of heat control technology for the high energy COIL.更多还原