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CN-121994365-A - Total reflection type collinear ultrashort pulse time domain sampling device and method

CN121994365ACN 121994365 ACN121994365 ACN 121994365ACN-121994365-A

Abstract

The invention relates to the technical field of ultra-short pulse time domain sampling, in particular to a total reflection type collinear ultra-short pulse time domain sampling device and a method, by adopting a total reflection type optical path design, all key optical elements work based on a reflection principle, the dispersion problem introduced by the transmission element is fundamentally eliminated, so that the original time domain and frequency domain characteristics of the pulse to be measured can be maintained in the measuring process, the high fidelity and reliability of the measuring result are ensured, the whole structure is simple, the operation is convenient, and the working efficiency is improved.

Inventors

  • HUANG PEI
  • Wu Yangyifan
  • FU YUXI
  • XIA YUFENG
  • Zou Rucheng
  • WU GUOWEI
  • LIU BEN
  • HOU XUAN

Assignees

  • 中国科学院西安光学精密机械研究所

Dates

Publication Date
20260508
Application Date
20260206

Claims (10)

  1. 1. A totally reflective collinear ultrashort pulse time domain sampling device, comprising: the laser (1) is used for generating a pulse to be detected, and the pulse to be detected is an ultrashort pulse; The beam splitting assembly is arranged on an emergent light path of the laser (1) and is used for splitting an incident pulse to be detected into a first sub-pulse beam and a second sub-pulse beam which are transmitted in a collinear manner in space, wherein the first sub-pulse beam is a solid beam, and the second sub-pulse beam is an annular beam; The delay adjusting mechanism (3) is connected with the light splitting assembly and is used for adjusting the relative optical delay between the first sub-pulse light beam and the second sub-pulse light beam; The focusing reflector (4) is arranged on the reflecting light path of the light splitting assembly and is used for focusing the first sub-pulse light beam and the second sub-pulse light beam which are transmitted in a collinear way into a nonlinear medium at the same time so as to generate nonlinear signal light; the filter component (5) is arranged on the emergent light path of the nonlinear signal light and is used for filtering fundamental frequency light and transmitting the nonlinear signal light; and the detection assembly is used for receiving and analyzing the nonlinear signal light so as to acquire the time domain characteristics of the pulse to be detected.
  2. 2. The totally reflecting collinear ultra-short pulse time domain sampling device according to claim 1, characterized in that the light splitting assembly comprises an inner and an outer mirror (2), the inner and outer mirrors (2) comprising: An endoscope, wherein the diameter range of the endoscope is 2-5mm; The outer mirror is provided with a through hole in the center, the diameter of the through hole is larger than that of the inner mirror, and the outer mirror and the inner mirror are movably arranged; the external mirror is used for reflecting the pulse to be detected to form the second sub-pulse beam, and the first sub-pulse beam and the second sub-pulse beam are coaxially transmitted.
  3. 3. The totally reflecting collinear ultrashort pulse time domain sampling device according to claim 2, wherein the delay adjusting mechanism (3) is a piezoelectric ceramic translation stage, the endoscope is fixedly mounted on the piezoelectric ceramic translation stage, and the piezoelectric ceramic translation stage changes the optical path length of the first sub-pulse beam by driving the endoscope to translate.
  4. 4. The total reflection type collinear ultra-short pulse time domain sampling device according to claim 1, wherein the focusing mirror (4) is a concave silver mirror, and the focal length of the focusing mirror (4) is 100mm.
  5. 5. The totally reflecting collinear ultra-short pulse time domain sampling device according to claim 1, wherein the nonlinear medium is air and the nonlinear signal light is frequency tripled light.
  6. 6. The totally reflecting collinear ultra-short pulse time domain sampling device according to claim 1 or 5, characterized in that the filtering component (5) is a frequency tripler filter.
  7. 7. The total reflection co-linear ultrashort pulse time-domain sampling apparatus of claim 1, wherein the detection assembly comprises: A converging mirror (6) for converging the nonlinear signal light after filtering; And the spectrometer (7) is used for receiving the converged nonlinear signal light and performing spectral analysis.
  8. 8. The totally reflecting collinear ultra-short pulse time domain sampling device according to claim 7, characterized in that the converging mirror (6) is a concave silver mirror with a focal length of 50mm.
  9. 9. A method for measuring time domain characteristics of ultrashort pulses, wherein a total reflection type collinear ultrashort pulse time domain sampling device as defined in any one of claims 1 to 8 is used, and the method comprises the following steps: dividing the pulse to be measured into a first sub-pulse beam and a second sub-pulse beam which are transmitted in a collinear way by utilizing the light splitting component; Continuously varying the relative delay between the first sub-pulse beam and the second sub-pulse beam by the delay adjustment mechanism (3); Recording the intensity of nonlinear signal light generated by the nonlinear effect at each delay; And obtaining the pulse width and spectral phase information of the pulse to be detected through Fourier transform data processing according to the change relation of the nonlinear signal light intensity along with the time delay.
  10. 10. The measurement method according to claim 9, wherein the nonlinear signal light is a frequency tripled light; the method for obtaining the pulse width and spectrum phase information of the pulse to be detected through Fourier transform data processing according to the change relation of nonlinear signal light intensity along with time delay specifically comprises the following steps: And carrying out Fourier transformation on the modulated signal with the frequency tripling light intensity along with the time delay to obtain the spectrum and the spectrum phase of the pulse to be detected, and further calculating the pulse width.

Description

Total reflection type collinear ultrashort pulse time domain sampling device and method Technical Field The invention relates to the technical field of ultra-short pulse time domain sampling, in particular to a total reflection type collinear ultra-short pulse time domain sampling device and method. Background In the field of ultrafast lasers, accurate measurement of ultrashort laser pulses is of great importance, and the method is not only a core driving force for promoting development of the field, but also a foundation stone for connecting a microscopic ultrafast process with macroscopic observation. The width of the ultra-short pulse, especially the femtosecond or attosecond pulse, is far faster than the response limit of the electronic detector, and key parameters such as the intensity, the phase, the pulse width, the chirp and the like of the pulse cannot be accurately obtained, so that the active compression and the shaping of the pulse form are realized. The accurate measurement of the ultra-short pulse ensures the reliability and accuracy of ultra-fast spectrum experimental data such as pumping-detection and the like, so that the direct observation of physical and chemical ultra-fast processes such as chemical bond fracture, charge transfer, energy relaxation and the like which are invisible once becomes possible, the control capability based on the accurate measurement directly promotes the forward disciplines such as attosecond physics, intense field physics and the like, and the development of application technologies such as precise micromachining, biological imaging, future ultra-high speed optical communication and the like is strongly promoted. Measurement of ultrashort pulses is a real understanding and exploitation of the interaction of light with matter on an extreme time scale, and the whole ultrafast field will lose the "time scale" on which it depends to survive. In the existing ultra-short laser pulse measurement technology, the main stream methods such as an autocorrelation instrument, a frequency resolution optical switch (FROG) and a spectral phase interference direct electric field reconstruction method (SPIDER) are commonly adopted, and the optical path structure based on a Mach-Zehnder interferometer is generally adopted. The core principle is that the pulse to be detected is split into two paths, and a controllable time delay is introduced into one path, and then the two paths of pulses are combined in a nonlinear crystal to generate an autocorrelation signal. However, the practical application of the classical scheme faces two major challenges, namely, firstly, the precise superposition and alignment of two light paths are required to be realized in space, and the arm length of an interferometer is required to be precisely adjusted in submicron level, the whole device has complex construction process and extremely high requirements on mechanical stability, and secondly, the transmission optical elements such as a beam splitter, a beam combiner and the like which are indispensable in a measuring system inevitably introduce extra dispersion into the pulse to be measured, so that the characteristics of the pulse are changed, and the accuracy and the reliability of a final measuring result are directly influenced. Disclosure of Invention The invention aims to provide a total reflection type collinear ultra-short pulse time domain sampling device and method, which solve the technical problem that transmission components introduce chromatic dispersion in ultra-short laser pulse measurement. The invention solves the technical problems as follows: A totally reflective collinear ultrashort pulse time domain sampling device, comprising: The laser is used for generating a pulse to be detected, and the pulse to be detected is an ultrashort pulse; The beam splitting assembly is arranged on an emergent light path of the laser and is used for splitting an incident pulse to be detected into a first sub-pulse beam and a second sub-pulse beam which are transmitted in a collinear way in space, wherein the first sub-pulse beam is a solid beam, and the second sub-pulse beam is an annular beam; the delay adjusting mechanism is connected with the light splitting assembly and used for adjusting the relative optical delay between the first sub-pulse light beam and the second sub-pulse light beam; the focusing reflector is arranged on the reflecting light path of the light splitting assembly and is used for focusing the first sub-pulse light beam and the second sub-pulse light beam which are transmitted in a collinear way into a nonlinear medium at the same time so as to generate nonlinear signal light; The filter component is arranged on the emergent light path of the nonlinear signal light and is used for filtering fundamental frequency light and transmitting the nonlinear signal light; and the detection assembly is used for receiving and analyzing the nonlinear signal light so as to acquire the time