Large aperture femtosecond laser pulse width accurate measurement device

Abstract

The invention provides a large aperture femtosecond laser pulse width accurate measurement device comprising a light beam sampling screen which is arranged in turn along a light path. The light beam sampling screen samples the inputted large aperture femtosecond laser pulse light beams in a full aperture sampling mode or a partial aperture sampling mode; and the sampled light beams enter femtosecond laser pulse width measuring instrument through beam shrinkage and collimation of a first off-axis parabolic mirror and a collimating lens and the inputted femtosecond laser pulse width is measuredso that the large aperture femtosecond laser pulse width can be obtained. Full aperture measurement under the condition of large aperture can be realized and partial aperture measurement under the condition of large aperture can also be realized; besides, the sampling light path is the actual light path directly without introducing additional dispersion; and finally the measurement and beam shrinkage system performs beam shrinkage by using the first off-axis parabolic mirror with cooperation of the collimating lens without introducing additional dispersion or aberration so that the requirements of large aperture femtosecond laser pulse width accurate measurement can be quite conveniently met.

Description

technical field [0001] The invention relates to an accurate measurement device for the pulse width of a femtosecond laser with a large aperture. Background technique [0002] The compressed laser pulse width of the final physical target in the ultra-intense ultra-short femtosecond laser device is a very important technical index, which determines the real-time power and physical experiment effect when the laser pulse interacts with matter. The shorter the femtosecond laser pulse width, the higher the accuracy of the measured laser pulse width is required. [0003] With the further development of ultra-powerful and ultra-short femtosecond laser devices, the energy of compressed output laser pulses continues to increase, the width of laser pulses continues to shorten, and the output power continues to increase. In order to reduce the damage to compressed gratings due to increased output power, it is necessary Therefore, in general, the higher the output power of the femtoseco...

AI Technical Summary

Problems solved by technology

The reason is that in large-aperture femtosecond laser devices, spatial filters are generally used to filter out high-frequency costs and improve beam quality. If a transmission-type spatial filter is used, chromatic aberration will occur on the output wavefront, and there will be chromatic aberration in the system. In the case of small aperture sampling measurement, the chromatic aberration has little influence on the femtosecond laser pulse width, while in the case of large aperture sampling measurement, the chromatic aberration has a great influence on the femtosecond laser pulse width (it is the actual value of the measurement). In this case , the small-caliber measurement data is often much better than the large-caliber measurement data. If the small-caliber measurement data is used instead of the full-caliber measurement data, the measurement results will seriously deviate from the true value and cause large errors.

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