A method for broadening the ultraviolet supercontinuum by applying an external terahertz wave field

Abstract

The invention relates to a method for broadening an ultraviolet supercontinuum spectrum by additionally adding a TeraHertz wave field. A fundamental wave, a bi-color field and a three-color light field serve as an initial driving electric field, one synchronous weak TeraHertz wave electric field is added to the initial driving electric field, a silicon wafer is used for carrying out space beam combining on all light and TeraHertz waves, the beam combined light enters a vacuum cavity, nonlinear action is produced between the beam combined light and the gas medium jetted by a gas target to radiate higher harmonics, a metal filtering film is used for filtering other light out of the higher harmonics, and the needed higher harmonics are obtained. The symmetry of the adjacent half period of an original fundamental wave electric field can be changed more thoroughly through the TeraHertz waves, the motion path and the final recombination of electrons can be adjusted to a greater extent, the ultraviolet supercontinuum is efficiently broadened, the TeraHertz waves are suitable for all femtosecond light sources which can radiate higher harmonics, the linear chirp of an ultraviolet precision light spectrum can be guaranteed, later compression is convenient to carry out to obtain an ultrashort attosecond pulse, and even the zeptosecond time range can be achieved.

Description

technical field [0001] The invention relates to a high-order harmonic generation technology, in particular to a method for broadening the ultraviolet supercontinuum by applying a terahertz wave field. Background technique [0002] Femtosecond ultrafast laser is one of the important tools for people to study the atomic dynamics process inside molecules. Since the birth of the world's first laser in 1960, strong laser technology has developed rapidly. The development of strong lasers has gone through three stages: the first stage uses Q-switching technology to realize laser pulse output on the order of nanoseconds; the second stage uses active mode-locking technology to realize laser pulse output on the order of picoseconds; the third stage The stage is to obtain high-intensity femtosecond optical pulses through chirped pulse amplification technology. However, the ultrafast electronic processes of atoms and molecules generally occur on the order of attoseconds, while the lim...

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Problems solved by technology

[0005] The present invention aims at the problem that the width of the supercontinuum produced by high-order harmonics is not enough and cannot be adjusted effectively and conveniently, and proposes a method for broadening the ultraviolet supercontinuum by adding a terahertz wave field. The time-synchronized weak terahertz wave electric field can change the symmetry of the adjacent half-period of the initial driving electric field more thoroughly, so that the movement path and final recombination of electrons can be regulated to a greater extent, and the ultraviolet supercontinuum can be broadened efficiently , and is applicable to all femtosecond light sources that can radiate higher harmonics

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