Laser plasma optical device and method for generating ultra-short ultra-intense mid-infrared pulses

Patent metadata

Field	Value
Publication number	US-11523489-B2
Application number	US-202117170851-A
Country	US
Kind code	B2
Filing date	Feb 8, 2021
Priority date	Mar 4, 2020
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

Laser plasma optical device comprising a laser system for outputting driving light pulses and signal light pulses, a vacuum target chamber, a gas target generating device for generating gas and forming a required plasma channel target through high voltage capillary discharge ionization (or through laser picosecond pre-pulse ablation) of gas, and a focusing element. The driving light pulse is focused on the generated plasma channel target through the focusing element to generate a density-modulated plasma wake; and after a predetermined delay time T, the signal light pulse is focused onto a leading edge region of a second plasma density cavitation bubble of the plasma wake through the focusing element, so that the frequency of the signal light pulse is red-shifted to generate an ultra-intense near-single-cycle mid-infrared pulse.

First claim

We claim:

1. A laser plasma optical device, comprising:
a laser system for outputting driving light pulses and signal light pulses;
a vacuum target chamber for providing a vacuum environment for interaction of laser and matter;
a gas target generating device disposed in the vacuum target chamber, the gas target generating device being used for generating gas and forming a plasma channel target along a propagation direction of a driving light pulse by a laser pre-pulse irradiation or by a high-pressure ionized gas; and
a focusing element disposed in the vacuum target chamber,
wherein the driving light pulse is focused onto the plasma channel target by the focusing element to generate a density-modulated plasma wake;
after a predetermined delay time T, the signal light pulse is focused onto a leading edge region of a second plasma density cavitation bubble of the density-modulated plasma wake through the focusing element, so that frequency of the signal light pulse is red-shifted to generate a near-single-cycle mid-infrared pulse with relativistic intensity and single-pulse energy up to multi-millijoule.

2. The laser plasma optical device of claim 1 , wherein the plasma channel target has a density rising radial density gradient distribution in a radial direction of a channel and a substantially uniform axial density distribution in an axial direction of the channel.

3. The laser plasma optical device of claim 1 , wherein the leading edge region is within most front end or a first half region of the second plasma cavitation bubble of the plasma wake.

4. The laser plasma optical device of claim 1 , wherein a beam waist radius where the driving light pulse and the signal light pulse are focused on the plasma target is 5-30 micrometers.

5. The laser plasma optical device of claim 1 , wherein the predetermined delay time T is adjusted in a range of tens of femtoseconds.

6. The laser plasma optical device of claim 1 , wherein the peak power of the driving light pulse is 1-20 terawatts.

7. The laser plasma optical device of claim 1 , wherein the peak power of the signal light pulse is 0.1-15 terawatts.

8. The laser plasma optical device of claim 1 , wherein the gas target generating device is a controllable high pressure gas nozzle device or capillary channel device.

9. The laser plasma optical device of claim 1 , wherein the mid-infrared pulse comprises one or more characteristics selected from the group consisting of (a) a peak intensity exceeding 10 17 watts/cm 2 ; (b) a pulse width being short to near a single optical cycle at the half-height full width position of the light intensity; (c) total energy up to dozens of millijoules; (d) a central wavelength up to 5 micrometer, and the maximum cut-off wavelength up to 10 micrometer; and (e) a controllable carrier phase.

10. A method for generating a near-single-cycle mid-infrared pulse with relativistic intensity and single-pulse energy up to multi-millijoule, comprising
(a) providing a gas target to generate a plasma channel target through laser pre-pulse irradiation or high-pressure ionization of the gas target;
(b) providing a driving light pulse to focus onto the gas target or the plasma channel target formed by the gas target in step (a) to generate a density-modulated plasma wake; and
(c) after a predetermined delay time T, providing a signal light pulse to focus onto a leading edge region of a second plasma density cavitation bubble of the plasma wake in step (b) to red-shift a frequency of the signal light pulse to generate a near-single-cycle mid-infrared pulse with relativistic intensity and single-pulse energy up to multi-millijoule.

Assignees

• Univ Shanghai Jiaotong

Inventors

• Zhu Xinglong
• Weng Suming
• Chen Min
• Sheng Zhengming
• Zhang Jie

Classifications

• H01S3/0092

  Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity (nonlinear frequency conversion per se G02F1/35) · CPC title

• H01S5/0615

  Q-switching, i.e. in which the quality factor of the optical resonator is rapidly changed · CPC title

• H01S3/0085 Primary

  Modulating the output, i.e. the laser beam is modulated outside the laser cavity · CPC title

• G02F1/35 Primary

  Non-linear optics · CPC title

• H01S5/0085

  for modulating the output, i.e. the laser beam is modulated outside the laser cavity · CPC title