Imaging device and ultra-short pulse sequence generation method

Abstract

The invention discloses an imaging device and an ultra-short pulse sequence generation method. A photonic crystal fiber receives ultra-short laser pulses emitted by a laser, and the spectrum of the inputted ultra-short laser pulses is stretched; a pulse compressor compressed the pulse width of the ultra-short laser pulses outputted by an ultra-continuous spectrum generator after spectrum stretching; a pulse stretcher carries out chirped stretching on ultra-short laser pulses outputted by the pulse compressor after pulse width compression; and a pulse shaper carries out spatial dispersion and spectrum shaping on the ultra-short laser pulses outputted by the pulse stretcher after chirped stretching, the ultra-short laser pulses after spectrum shaping are inverted to time chirped pulses, and a chirped ultra-short pulse sequence is generated. According to the imaging device and the ultra-short pulse sequence generation method disclosed by the invention, the spectrum width of the ultra-short laser pulse source can be effectively increased, the ultra-short pulse sequence whose sub pulse width is smaller than hundred femtosecond is generated, and ultra-fast resolution imaging can be realized.

Description

technical field [0001] The invention relates to the field of fast imaging devices, in particular to an imaging device and an ultrashort pulse sequence generation method. Background technique [0002] Using rapid imaging technology to photograph the process of the occurrence and development of things, and then conduct detailed analysis, can realize "visualization of the invisible process", thereby deepening the understanding of the process of the occurrence and development of things. In order to meet the needs of scientific research and industrial applications, high-speed imaging technology has been rapidly developed and commercialized products have been developed in recent decades. Generally speaking, conventional rapid imaging technology is divided into two categories: one is continuous mode camera (such as high-speed video recorder), which can continuously take a large number of photos and store them in digital memory; the other is trigger mode camera (such as framing came...

AI Technical Summary

Problems solved by technology

There are two points for improvement: one is that the spectral width of the ultrashort pulse light source is not wide enough. The spectral width of the ultrashort pulse light source is about 20nm. After being divided into multiple sub-pulses, the spectral width of each sub-pulse is even smaller. After the pulse is recompressed, the pulse width will be wider, and different sub-pulses will overlap in time waveform, which will lead to the overlap of captured image information, thus limiting the minimum time resolution that can be finally achieved; the second is through space In the process of spectrum shaping by means of shaping, the transmittance distribution of the space shaping device has not been finely optimized, which is one of the reasons for the overlapping of sub-pulse waveforms, and will eventually limit the minimum time resolution capability

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