Terahertz modulation induced by filament interaction

He, Bei; Nan, Junyi; Li, Min; Yuan, Shuai; Zeng, Heping

doi:10.1364/ol.42.000967

Cited by 17 publications

(6 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the current experimental study, He et al introduces another laser pulse of 800 nm into the conventional two-color setup, and through changing the polarization and energy of the introducing laser pulse, the spatial plasma density can be modulated, and thus changing the THz spectral shape. [36] Therefore, we believe that our uncommon multi-color scheme can be used for further experimental studies and provide a way of studying the intense and shaped THz generation.…”

Section: Resultsmentioning

confidence: 95%

Enhancement and modulation of terahertz radiation by multi-color laser pulses

Pei

Wang

et al. 2018

Chinese Phys. B

View full text Add to dashboard Cite

We study theoretically intense terahertz radiation from multi-color laser pulse with uncommon frequency ratios. Comparing the two-color laser scheme, of which the uncommon frequency ratio should be set to be a specific value, we show that by using multi-color harmonic laser pulses as the first pump component, the lasers as the second pump component can be adjusted in a continuous frequency range. Moreover, these multi-color laser pulses can effectively modulate and enhance the terahertz radiation, and the terahertz yield increases with the increase of the wavelength of the uncommon pump component and is stable to the laser relative phase. Finally, we utilize the electron densities and velocities of ionization events to illustrate the physical mechanism of the intense terahertz generation.

show abstract

Section: Resultsmentioning

confidence: 95%

Enhancement and modulation of terahertz radiation by multi-color laser pulses

Pei

Wang

et al. 2018

Chinese Phys. B

View full text Add to dashboard Cite

show abstract

“…A frequency-doubling β -BBO (200 μm, type I) was inserted between lens and filament, leading to second harmonic generation. THz emission from dual-color filament [24,25] was used as the probe pulse to measure the refractive index of substrates. The THz probe pulses were focused onto the back surface of sample by a pair of parabolic mirrors.…”

Section: Resultsmentioning

confidence: 99%

Terahertz and Photoelectron Emission from Nanoporous Gold Films on Semiconductors

Nan

Zhang

et al. 2019

Nanomaterials

Self Cite

View full text Add to dashboard Cite

Efficient terahertz and photoelectron emission were observed from nano-porous gold (NPG) films deposited on an intrinsic gallium arsenide (GaAs) semiconductor substrate stimulated by femtosecond laser with pulse width of 60 fs. Time-domain THz emission and reflection spectroscopy confirmed that the free charges accelerated by irradiated femtosecond laser pulses transferred from the NPG films into the GaAs substrates. Accordingly, charges accumulation was reduced in the NPG films, resulting in a stronger emission of THz pulse than that from NPG films deposited on SiO2 substrate. Charges injected into the GaAs substrate enforced an observable decrease of the THz refractive index proportional to the intensity of incident light. In comparison, for NPG deposited on glass substrates, laser induced free charges were accumulated in the NPG films, and femtosecond laser pulses irradiating on the NPG films made no changes of the THz refractive index of the glass substrates.

show abstract

“…与单色场技术相比, 双色场技术可将太赫兹波的振幅提高约40倍 [29] . 基于双色场技术, 现阶段对于太赫兹波的整形调控方法大致分为两类: 一种是直接调控方式, 例如采用太赫兹波调控器件, 能够直接改变入射太赫兹波的各种参数 [30][31][32][33][34] ; 另一种为间接调控方式, 通过改变产生太赫兹波的泵浦激光的各种参数或者在太赫兹波的产生区域处施加外部电场或磁场来进行调控 [35][36][37][38][39] . Clerici等 [40] 发现了调控双色激光的波长可以提高太赫兹波的转换效率.…”

Section: 体材料本身电离击穿的阈值限制而基于等离子体的太赫兹源不受损伤阈值的影响可以产生场强接unclassified

Theoretical study of influence of laser pulse chirp on terahertz emission characteristics of gas induced by two-color laser field

Li,

Peng

2024

Acta Phys. Sin.

View full text Add to dashboard Cite

With the development of terahertz (THz) wave research, the demand for controllable THz sources is increasing. How to obtain the regulated THz waves has been one of the research hotspots and key problems in the field of THz science. There have been researchers who modulate the resulting THz waves by changing the wavelength, relative phase, energy, or chirp of the laser produced by a two-color laser. In this paper, we establish a three-dimensional theoretical model of THz wave generation and subsequent propagation induced by two-color laser. And we investigate the influence of chirp modulation of different laser on THz waves by chirp modulation of fundamental wave (FW) and the second harmonic wave (SHW) respectively of two-color laser. Including THz waves amplitude, THz waves center frequency and spectrum width, and analyze the physical mechanism of related phenomena. At the same time, the effects of different orders of magnitudes of laser chirp parameters (femtosecond and picosecond) and initial phase of laser pulse on THz waves parameters are also studied. The results of study show that: 1) In the two-color laser, the chirp of FW mainly affects the shape of THz waves when the initial phase is unchanged. Chirp modulation of SHW can cause significant changes in the amplitude of THz waves, and affect the center frequency and spectrum width of THz waves. 2) In the case of laser pulse width of femtosecond order, 40 fs is taken as an example. When the chirp parameter is femtosecond magnitude, the chirp parameter has a great influence on the THz waves generation efficiency of two-color laser filament. At the picosecond magnitude, the chirp parameter has a weak effect on the THz waves energy and mainly affects the phases of the THz waves. 3) The initial phase of the two-color laser can be aided in chirp modulation of THz waves to optimize the energy generated. 4) The initial phase of two-color laser can be assisted in the process of chirped laser modulation of terahertz waves to optimize the energy generated. Our study shows that the chirp modulation, as a controllable parameter, has multiple regulatory effects on the properties of radiated THz waves. The related study results provide a new idea and basis for the study on the generation and regulation of THz waves.

show abstract

Terahertz modulation induced by filament interaction

Cited by 17 publications

References 37 publications

Enhancement and modulation of terahertz radiation by multi-color laser pulses

Enhancement and modulation of terahertz radiation by multi-color laser pulses

Terahertz and Photoelectron Emission from Nanoporous Gold Films on Semiconductors

Theoretical study of influence of laser pulse chirp on terahertz emission characteristics of gas induced by two-color laser field

Contact Info

Product

Resources

About