Towards Terawatt-Scale Spectrally Tunable Terahertz Pulses via Relativistic Laser-Foil Interactions
| Autor: | David Neely, Peter G. Huggard, Y. T. Li, Dean Rusby, Graeme Scott, Zheng-Ming Sheng, Philip Bradford, Wei-Min Wang, Nigel Woolsey, Egle Zemaityte, Jie Zhang, Ceri Brenner, Paul McKenna, Zhe Zhang, Baojun Zhu, Chris Armstrong, Guoqian Liao, Liu Hao, Yi Hang Zhang |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
business.industry Terahertz radiation Physics QC1-999 General Physics and Astronomy Electron Laser 01 natural sciences 010305 fluids & plasmas law.invention Coherent control law Brightness temperature 0103 physical sciences Optoelectronics Transient (oscillation) Irradiation 010306 general physics business Ultrashort pulse QC |
| Zdroj: | Physical Review X, Vol 10, Iss 3, p 031062 (2020) |
| ISSN: | 2160-3308 |
| Popis: | An ever-increasing number of strong-field applications, such as ultrafast coherent control over matter and light, require driver light pulses that are both high power and spectrally tunable. The realization of such a source in the terahertz (THz) band has long been a formidable challenge. Here, we demonstrate, via experiment and theory, efficient production of terawatt (TW)-level THz pulses from high-intensity picosecond laser irradiation on a metal foil. It is shown that the THz spectrum can be manipulated effectively by tuning the laser pulse duration or target size. A general analytical framework for THz generation is developed, involving both the high-current electron emission and a time-varying electron sheath at the target rear, and the spectral tunability is found to stem from the change of the dominant THz generation mechanism. In addition to being an ultrabright source (brightness temperature of about 10^{21} K) for extreme THz science, the THz radiation presented here also enables a unique in situ laser-plasma diagnostic. Employing the THz radiation to quantify the escaping electrons and the transient sheath shows good agreement with experimental measurements. |
| Databáze: | OpenAIRE |
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