线刃型位错光束在生物组织中的光学奇异性

Optical singularity of wire-edged dislocation beams in biological tissue

采用推导在生物组织传输中的线刃型位错高斯谢尔模型光束的交叉谱密度函数,研究了不同线刃型位错斜率p、离轴距离d对光束奇异性的影响,讨论了归一化光强和相位随传输距离L的演变规律。研究表明,传输中,光束光强分布轮廓由非轴对称分布的中心凹陷逐渐演变为中心凹陷消失,最终呈现类椭圆高斯分布。线刃型位错离轴距离d值越大,源平面处两峰值光强差别越大,中心凹陷越不明显且偏离(0,0)越大,传输中的光强演化越快。同时,随着d值增大,传输中相干涡旋的演化由出现两次湮灭现象变为一次;当离轴距离d较小时,d值越大,发生第一次湮灭越晚,相干涡旋对再次出现越早;相干涡旋对位置的连线沿顺时针方向旋转,p越大,旋转越快;d值越大,p值越小,相干涡旋最终湮灭越早。

By deducing the cross spectral density function of Gaussian Schell model beam with line-edge dislocation in biological tissue transmission,the effects of different line-edge dislocation slope and off-wheelbase separation on beam singularity are studied,and the evolution law of normalized light intensity and phase with transmission distance is discussed.The results show that during transmission,the beam intensity distribution profile gradually evolves from the central depression of the non-axisymmetric distribution to the central depression disappears,and finally presents an elliptical-Gaussian-like distribution.The larger the off-axis distance of the line edge dislocation,the greater the difference in light intensity between the two peaks at the source plane,the less obvious the central depression and the greater the deviation(0,0),and the faster the light intensity evolution in transmission.At the same time,as the value increases,the evolution of the coherent vortex in transport changes from two annihilations to one.When the offaxis distance is small,the larger the value,the later the first annihilation occurs,and the earlier the coherent vortex pair appears again.The line of the coherent vortex pair rotates clockwise,the larger the rotation,the faster the rotation;the higher the value,the smaller the value,and the sooner the coherent vortex eventually annihilates.