High-contrast pulse measurement method and device

Abstract

The present invention relates to a high-contrast pulse measurement method and device. The method is characterized in that a beam splitting device divides a to-be-measured pulse into two same pulses, one pulse is modulated and outputted by a modulator, and a time delay device carries out the time delay on the other pulse; finally, the two pulses are combined by a beam combination device and then are connected with a spectrum analyzer; modulation signals from high to low or from low to high changing along with the time delay length are obtained on the spectrum analyzer and are the pulse autocorrelation signals represented in a logarithm format, and by the computer analysis and processing, the width and the contrast of the to-be-measured pulse are finally obtained. According to the present invention, a conventional method of utilizing the non-linear effect of a frequency doubling crystal to measure the autocorrelation signals is avoided, the interference of the noise signals introduced by the non-linear effect is reduced, and not only the width of the pulse can be measured, but also the contrast of the pulse can be distinguished directly, so that the measurement is more accurate, and the error amount is smaller.

Description

technical field [0001] The invention relates to a laser parameter measurement technology, in particular to a high-contrast pulse measurement method and a measurement device. Background technique [0002] In recent years, with the continuous advancement of laser technology, laser pulses are constantly developing in the direction of ultrashort pulse lasers. In the fields of physics, chemistry and biology, using femtosecond pulsed lasers to observe various dynamic processes, various ultrafast phenomena and biological imaging processes has become an important means of research. The accuracy of pulse width measurement will greatly affect the accuracy of various observations, so the precise measurement of pulse width is particularly important. [0003] Based on the current technical means, the current instrument for measuring laser pulse width is mainly autocorrelator. Autocorrelator is compact in structure, easy to use, and has high resolution and sensitivity. It is the main met...

AI Technical Summary

Problems solved by technology

However, the pulse width or pulse contrast measured by this method also has some shortcomings. When the intensity of the signal to be measured is low, it may cause The signal obtained by multiplication or sum frequency is too low

This will lead to inaccurate measurement of the autocorrelation signal of the pulse width or the inability to measure the autocorrelation signal due to the influence of the noise signal

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