光强非均匀分布对波前曲率传感器的影响

Influence of Nonuniform Intensity on Wavefront Curvature Sensor

为了将波前曲率传感器用于涉及激光波前的领域,理论分析了非均匀光强入射条件下的曲率传感器测量信号。用菲涅耳衍射公式,数值计算了相位分布为前10阶泽尼克多项式,光强为高斯分布和正态随机分布闪烁的曲率传感器信号,并和相同相位分布,光强均匀情况下的传感器信号比较。分析表明光强非均匀分布给波前曲率传感器测量信号带来了一定的误差。光强高斯分布对散焦相差的曲率信号影响较大,信号百分比误差达到25%,对其他相差的曲率信号影响很小;对于有正态随机分布闪烁的光强分布,信号百分比误差与正态随机分布的均方差成线性关系。在一定条件下,波前曲率传感器也能够用于光强非均匀分布的领域。

In order to utilize the wavefront curvature sensor in the field of laser wavefront theoretical analysis for the signal of wavefront curvature sensor under the illumination of nonuniform intensity is made. By means of Fresnel diffraction, signal of wavefront curvature sensor is computed under the conditions that the first 10 Zernike polynomials phase profile, and Gaussian distribution or normal random distribution intensity profile, and then compared with the signal with the same phase profile but uniform intensity profile. Analysis indicates that nonuniform intensity introduces some error into wavefront curvature sensor signal. Intensity of Gaussian distribution impacts significantly the sensing signal of the defocus phase, in which the error percentage achieves 25 %, but for other phase profile, the effect is ignorable. Illuminated by the normal random scintillation, there is a linear relation between the error percent and the root mean square of the normal random distribution, Under some given conditions, the wavefront curvature sensor also can be utilized in the field of illumination of nonuniform intensity.