【摘要】 根据Li提出的平顶光束模型和部分相干光理论,推导出部分相干平顶光束在线性增益(损耗)介质中传输的光谱分布解析表达式,定量研究了部分相干平顶光束在线性增益(损耗)介质中传输的光谱特性,分析了近场和远场轴上光谱的变化特点,以及介质的增益(损耗)特性、光源的中心频率、空间相干参数以及谱宽等因素对光谱变化的影响.研究结果表明,部分相干平顶光束在线性增益(损耗)介质中传输时,光源的中心频率、光谱宽度、空间相干参数对相对谱移量影响较大,但对光谱分布随传输距离的总体变化趋势影响较小,而光谱分布随传输距离的总体变化趋势则主要由平顶光束的阶数所决定.更多还原

【Abstract】 Based on the flat_topped beams model proposed by Li and the propagation theory of partially coherent light,the spectrum analytical expression of partially coherent flat_topped beams propagating in the linear gain or loss media was derived and the spectral properties were studied quantitatively by numerical calculation. The variation characteristics of the on_axis spectrum in near_ and far_field regions have been discussed in details. The effects of the property of the linear gain or loss media and some parameters of the light source,such as the central frequency,spectrum width and spatial coherence parameter on the spectral shift have also been discussed. It can be shown that the light source parameters have greater effects on the value of the frequency shift than on the total changing trend of the spectrum along the propagation distance,whereas the latter is determined by the beam order of flat-topped beam.更多还原