部分相干电磁光束在线性增益(损耗)介质中的传输特性

The Properties of Partially Coherent Electromagnetic Beams Propagating in Linear Gain or Loss Media

根据Wolf提出的电磁光束模型和部分相干光理论,以电磁高斯-谢尔模型光束为例,推导出光束在线性增益(损耗)介质中传输的交叉谱密度矩阵,研究介质传输场中强度和偏振度的变化特点.研究结果表明,任意电磁光束在线性增益(损耗)介质中传输时,当其为增益(损耗)介质时,会增强(衰减)光束的强度;但对偏振度却没有太大的影响.波数实部Kr越小,轴上偏振度越大;相干长度δyy越小,轴上偏振度越大.当光源处的相干长度xδx与δyy取值相同时,尽管传输距离不断增大,光束在传输过程中的偏振度不发生变化.光源处的偏振度P(0)越大,轴上偏振度也越大.

Based on the electromagnetic beams model proposed by Wolf and the propagation theory of partially coherent light, by taking electromagnetic Gaussian Schell-model （EGSM） beams as an example, the expression for the cross-intensity matrix of the beam propagating in linear gain or loss media was derived. The variation characteristics of spectral density and degree of polarization in linear gain or loss media have been studied. It can be shown that, the stochastic electromagnetic beams propagating in linear gain or loss media, when the media property is gain （loss）, it will heighten （lower） the spectral density; but it has iittle of no effect on the degree of polarization. The effects of the wave number K, or the source coherence length is smaller, the axis degree of polarization is greater. When the values of the coherence length δxx and δxr are the same, even though the transmission distance increasing, the degree of polarization does not change. The greater the source degree of polarization p^（0） , the axis degree of nolarization is greator