45 results about "Attosecond pulse" patented technology

The invention relates to a method for measuring the pulse width of attosecond pulse, including the following steps: 1) beam combining light composed of laser and the attosecond pulse is focused on a noble gas, and formed into a photoelectronic signal containing attosecond pulse information by single photon ionization; 2) the photoelectronic signals are collected to obtain a photoelectron spectrum; 3) the photoelectron spectrum is analyzed by utilizing the relational formula of the photoelectron spectrum and the attosecond pulse so as to obtain the pulse width of the attosecond pulse. The method of the invention establishes the direct relation between the photoelectron spectrum and the attosecond pulse, and obtains the pulse width of the attosecond pulse by measuring the photoelectron spectral width; the proposal simplifies the measuring method and avoids massive fitting computation, and the measuring result is precise.

The invention relates to the direction of ultrafast laser technique, concretely relating to an intracavity higher harmonics generating method, directly placing nonlinear medium in a laser oscillator to obtain higher harmonics, and able to obtain few-cycle laser pulses because in the laser oscillator, the dispersion caused by cavity mirror and medium can be perfectly compensated, thus more beneficial to generation of higher harmonics, where the few-cycle laser pulses can obtain UV comb on the condition of locking carrier wave phase and can obtain single attosecond pulses.

A system and method for performing four dimensional multicolor nanotomography with high harmonics and attosecond pulses to attain spectrally resolved absorption data about the three-dimensional volumetric structure of a sample are disclosed. Also disclosed are embodiments of the system and method that have been adapted to perform four dimensional multicolor nanotomography absorption and index of refraction data about the three-dimensional volumetric structure of a sample, to perform five dimensional multicolor nanotomography with high harmonics and attosecond pulses to obtain spectrally resolved absorption data about the three-dimensional volumetric structure and temporal dynamics of the sample, to perform five dimensional multicolor nanotomography to obtain spectrally resolved absorption and index of refraction data about the three-dimensional volumetric structure and temporal dynamics of the sample, and to perform Fourier-domain Optical Coherence Tomography.

The invention discloses an attosecond pulse measuring method and a device thereof. The method comprises the following steps: enabling a beam of weak femtosecond pulse to act on the generation processof attosecond pulse to be measured, so as to change the accumulated phase of ionized free electrons in a free state in the generation process of the attosecond pulse to be measured and to carry out the perturbation of the attosecond pulse frequency spectrum to be measured, wherein the weak femtosecond pulse is a femtosecond pulse with the intensity being within a preset intensity range; adjustingthe relative time delay between the weak femtosecond pulse and a driving field used for generating the attosecond pulse to be measured to obtain a two-dimensional trace graph of the attosecond pulse frequency spectrum to be measured changing along with the relative time delay; and extracting complete time domain structure information of the attosecond pulse to be measured from the two-dimensionaltrace graph through a reconstruction algorithm. According to the method, a beam of extra weak femtosecond pulse is introduced to carry out perturbation on the generation process of a single attosecondpulse, a two-dimensional diagram of single attosecond frequency spectrum changing along with time delay is obtained by changing relative time delay between the two beams of pulse, and finally the time structure information of the single attosecond pulse is extracted from the two-dimensional diagram through a PCGPA algorithm.

The invention discloses a method and a device for generating elliptically polarized attosecond pulses. A double-color laser field obtained by superposing the linearly polarized laser and the circularly polarized laser interacts with polar gas molecules, and an electric field parameter of the double-color laser field is calculated and adjusted by utilizing a three-dimensional time-containing schrodinger equation, so that the interaction generates higher harmonics; by adjusting the intensity ratio of the double-color laser field, the generated higher harmonics have the ellipsometry rate larger than the preset ellipsometry rate value in the cut-off region; and the higher harmonics with the ellipsometry rate larger than the preset ellipsometry rate value are synthesized into the attosecond pulse, and the ellipsometry rate of the attosecond pulse is regulated and controlled by adjusting the relative phase of the double-color laser field. According to the invention, high enough harmonic efficiency is ensured, and then elliptically polarized harmonic waves in a cut-off region are synthesized into high-efficiency elliptically polarized isolated attosecond pulses. Besides, the method can realize regulation and control of the rotatability and ellipsometry rate of the isolated attosecond pulse by adjusting the relative phase of the double-color field, and is a practical method for generating and adjusting the ellipsometry isolated attosecond pulse.

This invention relates to a method for generating high-order harmonic waves utilizing the non-collinear non-linear conversion property of medium, which utilizes the mixing property of non-linear beams to lead out high order harmonic waves from the cavity without additional operations in the emitted non-linear medium. The advantage is that it is easier to pick up pure high-order harmonic wave composition to obtain the harmonic waves under the multi-color action and provide even higher laser peak power.

The invention discloses a method for measuring attosecond X-ray pulses and application of the method. According to the method disclosed by the invention, each measured related phase of a photoelectron is determined by using a parameterized computing formula, and the shape of a pulse and a concrete time structure are rebuilt through one step by using an analytical photoelectron spectrum unscrambling technology; and the time domain characteristics of the attosecond X-ray pulses can be rebuilt from each measured photoelectron spectrum without a large amount of time resolution measurements of a photoelectron spectrum and without a redundant iterative computation and an experimental data fitting process. The time uncertainty of a pulse measurement result is computed from energy bandwidth values of the pulses by using the parameterized formula. Because a direct relation among attosecond pulse time characteristics, important laser parameters (such as peak strength, electric field envelope shape, phase, carrier-envelope phase and the like), atomic or molecular ionization power and the photoelectron spectrum is established by a transformation equation, the method can be used for computing unknown parameters from each known parameter value.

A method and a device for dynamic compensation and pulse compression of higher harmonics intrinsic chirp are disclosed; in the method, the reshaping function of two colour laser fields on an electric field is used, when a weak frequency multiplication filed is overlapped on fundamental frequency light, the frequency multiplication filed introduces an additional phase item of a sin function form in the generating process of harmonic wave, the additional phase item can change from negative periodicity to positive periodicity along with the relatively delayed alteration between two colour fields, thus causing the chirp compensation of attosecond pulse to continuously change from negative to positive and obtaining the attosecond pulse of change limit. The invention not only can realize the compensation on attosecond pulse chirp but also can improve the generation efficiency of harmonics, and the invention is also suitable for single attosecond pulse below hundred attosecond.

The present invention relates to a double wavelength output optical parameter magnifying laser system with a stable carrier wave envelope phase, which has the characteristics that double wavelength with magnified parameters is used for producing and magnifying energy furthermore; therefore, double-wavelength ultrashort infrared pulses are output; the inherent CEP stable quality of idle light is used for obtaining the output of the CEP stable double-wavelength ultra-short infrared pulses. The double wavelength output optical parameter magnifying laser system with a stable carrier wave envelope phase has the advantages of simple operation, easy regulation, stable CEP, wide tune range and double-wavelength output. The double wavelength output optical parameter magnifying laser system with a stable carrier wave envelope phase provides wide light sources for the physics experiments such as the attosecond pulse production, etc.

The invention relates to a method, a system and a medium for measuring electron orbit radius based on attosecond fringe spectrum. The method includes acquiring the attosecond fringe spectrum generated by a plurality of infrared electric fields and a single attosecond pulse laser acting on a working gas respectively, and obtaining Under multiple electron initial positions, multiple classical fringe trajectories are generated by multiple infrared electric fields and a single attosecond pulsed laser acting on the working gas respectively; the photoionization time delay of the working gas is obtained according to the attosecond streak spectrum, and according to the multiple The multiple classical photoionization time delays corresponding to the working gas are obtained from each classical fringe trajectory; the electron orbital radii corresponding to the working gas are obtained according to the photoionization time delay and the multiple classical photoionization time delays. Based on the attosecond fringe spectrum, the invention can realize the direct measurement of the electron orbital radius. The method is simple in theory, low in calculation difficulty, small in calculation amount and high in precision.

A system and method for performing four dimensional multicolor nanotomography with high harmonics and attosecond pulses to attain spectrally resolved absorption data about the three-dimensional volumetric structure of a sample are disclosed. Also disclosed are embodiments of the system and method that have been adapted to perform four dimensional multicolor nanotomography absorption and index of refraction data about the three-dimensional volumetric structure of a sample, to perform five dimensional multicolor nanotomography with high harmonics and attosecond pulses to obtain spectrally resolved absorption data about the three-dimensional volumetric structure and temporal dynamics of the sample, to perform five dimensional multicolor nanotomography to obtain spectrally resolved absorption and index of refraction data about the three-dimensional volumetric structure and temporal dynamics of the sample, and to perform Fourier-domain Optical Coherence Tomography.