Fast convergence ultra-short pulse waveform and phase reconstruction method

Abstract

The invention relates to a fast convergence ultra-short pulse waveform and phase reconstruction method, which comprises the following steps of: optimizing a pulse initial guess value, preprocessing multiple grids of a two-dimensional trace graph, and reconstructing a pulse waveform and a phase by using a ptychographic iterative algorithm. After the optimized pulse initial guess value is utilized and the two-dimensional trace graph is preprocessed, the reconstruction calculation time of the two-dimensional trace graph is greatly shortened, the rapid convergence of the waveform and phase reconstruction of the ultra-short pulse can be realized, the requirement of the single real-time measurement of the ultra-short pulse is met, the reconstruction speed and the accuracy are ensured, and the method also has good noise immunity and high resolution.

Description

technical field [0001] The invention relates to an ultrashort pulse measurement method, in particular to an ultrashort pulse waveform and phase reconstruction method capable of fast convergence. Background technique [0002] The development of pulsed lasers has put forward higher requirements for laser measurement technology. In many application scenarios, it is necessary to obtain the spectral distribution and phase information of pulses to further study its transmission characteristics and the mechanism of interaction with matter. Therefore, the measurement of ultrashort pulses is very important. important and challenging. [0003] At present, the most practical, reliable and mature method is the frequency-resolved optical switching method (FROG), which can use various nonlinear processes to generate different types of trace (trace) diagrams for measurement, but the traditional pulse waveform and phase reconstruction of FROG The algorithm is not ideal, and there are still...

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Problems solved by technology

[0003]Currently the most practical, reliable and mature method is Frequency-Resolved Optical Switching (FROG), which can generate different types of traces (trace ) graph for measurement, but FROG is not ideal for traditional pulse waveform and phase reconstruction algorithms, and there are still many limiting factors in existing algorithms, such as convergence stagnation, reconstruction speed, etc.

In 2016, Pavel Sidorenko and Oren Lahav et al. proposed to use the ptychography recovery algorithm in coherent diffraction imaging to reconstruct the waveform and phase of ultrashort pulses. This method has ultra-high resolution, good noise resistance and robustness, but in practice When reconstructing ultrashort pulse intensity and phase, due to its slow speed, the measurement of ultrashort pulse waveform and phase has hysteresis. The measurement of the pulse and the further study of its transmission characteristics and the process of interacting with matter have brought a lot of trouble, so the research on the fast and accurate measurement of ultrashort pulses based on ptychography recovery algorithm is of great significance

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