Relativistic single-cycle tunable infrared pulses generated from a tailored plasma density structure

• DOI: 10.1038/s41566-018-0190-8
• Publication Date: 2018-06-08T14:23:23Z
• Authors: Zan Nie; Chih-Hao Pai; Jianfei Hua; Chaojie Zhang; Yipeng Wu; Yang Wan; Fei Li; Jie Zhang; Zhi Cheng; Qianqian Su; Shuang Liu; Yue Ma; Xiaonan Ning; Yunxiao He; Wei Lu; Hsu-Hsin Chu; Jyhpyng Wang; Warren B. Mori; Chan Joshi
• Keywords: Plasma Physics (physics.plasm-ph); FOS: Physical sciences; 7. Clean energy; Physics - Plasma Physics; Physics - Optics; Optics (physics.optics)

6 figures<br/>The availability of intense, ultrashort coherent radiation sources in the infrared region of the spectrum is enabling the generation of attosecond X-ray pulses via high harmonic generation, pump-probe experiments in the "molecular fingerprint" region and opening up the area of relativistic-infrared nonlinear optics of plasmas. These applications would benefit from multi-millijoule single-cycle pulses in the mid to long wavelength infrared (LW-IR) region. Here we present a new scheme capable of producing tunable relativistically intense, single-cycle infrared pulses from 5-14$��$m with a 1.7% conversion efficiency based on a photon frequency downshifting scheme that uses a tailored plasma density structure. The carrier-envelope phase (CEP) of the LW-IR pulse is locked to that of the drive laser to within a few percent. Such a versatile tunable IR source may meet the demands of many cutting-edge applications in strong-field physics and greatly promote their development.<br/>