为提高惯性约束聚变系统中聚焦光斑的能量集中度,分析了在应用过程中影响连续相位板性能的主要误差来源,并建立了相应的数学模型.通过分析得出存在误差时远场焦斑的能量集中度和均方根值,且口径误差、对准误差、振幅畸变误差对连续相位板的聚焦性能影响很小,波前畸变影响能量集中度的权重最大.进一步分析可知:当畸变波前相关长度与连续相位板的最小空间周期(10 mm左右)相当时,畸变波前极大地影响激光的聚焦性能,提高惯性约束聚变系统中畸变波前的相关长度是提高聚焦光斑的能量集中度的有效方法.%To improve the far field focal spot in inertiaf confinement fusion, the paper analyzes the main factors affecting the focusing performance of continuous phase plates. The encircled energy fraction and the far-field root-mean-square spot size are analyzed. The results show that, the aperture error, alignment error and amplitude distortion error have little effect on the focusing ability of continuous phase plates. The wavefront distortion lowers the energy concentrated especially when the correlation length is equivalent to the minimum spatial period (about 10 mm) of continuous phase plates. Thus improving the correlation length of the wavefront distortion in the inertial confinement fusion system is an effective way to improve the energy concentration degree of the foeal spot.
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