Continuous phase plate design method for full-frequency segmental control of focal spot

Abstract

The invention discloses a continuous phase board design method for focal spot full-frequency segmentation control. The method comprises steps: step one, setting a laser wavelength, near-field input distribution, an imaging focal length and far-field target distribution; step two, determining a continuous phase board size; step three, determining the processing process limit and designing a corresponding filter; step four, designing initial phase distribution of the continuous phase board according to step one; step five, designing a corresponding spectrum control function according to step one, step six, on the basis of a Fourier transform relationship, acquiring far-field distribution under the current phase board distribution and calculating a root mean square error of the top light intensity focal spot; step seven, carrying out spatial spectrum controlling on the far-field distribution; step eight, carrying out Fourier inversion to obtain input surface distribution; and step nine, repeating steps from the step six to the step eight to achieve a design objective, thereby completing the design. Therefore, the high efficiency design of the continuous phase board is realized; the defect of falling into local optimum by the design is overcome; and the method also can be applied to the designs of focal spots with different shapes.

Description

technical field [0001] The present invention relates to the technical field of continuous phase plates, in particular to a continuous phase plate design method for focal spot full-frequency subsection control, which can improve design efficiency and improve the defect that the design may fall into local optimum; and it can be used for focal spots of arbitrary shapes the design of. Background technique [0002] The research of inertial confinement fusion (ICF) puts forward very high requirements on the uniformity of light intensity and energy concentration of the laser focal spot on the target surface: the non-uniformity of light intensity under direct drive requires 1% to 2 %, the energy utilization rate is required to be greater than 90%; although the inhomogeneity requirement of the indirect drive can be reduced to 5% to 10%, the energy utilization rate must be greater than 95%, and the side lobe is required to be very small. Therefore, scholars at home and abroad have ca...

AI Technical Summary

Problems solved by technology

G-S and Y-G algorithms are simple in principle and have high computational efficiency, but are sensitive to initial conditions and parameters, and are prone to fall into local optimum; SA and GA algorithms are global search algorithms, but their computational efficiency is very low

[0004] Based on the above status quo, the present invention proposes a continuous phase plate design method for focal spot full-frequency segmental control, which can effectively control the low-frequency range, suppress the mid-frequency range, and relax the high-frequency range, which can not only improve the calculation efficiency, but also improve the possibility Trapped in local optima

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