We report the laser-chirp controlled terahertz(THz) wave generation from two-color-laser-induced air plasma.Our experimental results reveal that the THz wave is affected by both the laser energy and chirp,leading to r...We report the laser-chirp controlled terahertz(THz) wave generation from two-color-laser-induced air plasma.Our experimental results reveal that the THz wave is affected by both the laser energy and chirp,leading to radiation minima that can be quantitatively reconstructed using the linear-dipole-array model.The phase difference between the two colors,determined by the chirp and intensity of the laser,can account for the radiation minima.Furthermore,we observe an asynchronous variation in the generated THz spectrum,which suggests a THz frequency-dependent phase matching between the laser pulse and THz wave.These results highlight the importance of laser chirp during the THz wave generation and demonstrate the possibility of modulating the THz yields and spectrum through chirping the incident laser pulse.This work can provide valuable insights into the mechanism of plasma-based THz wave generation and offer a unique means to control THz emissions.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12174449,12225511,T2241002,12074250,11991073,12135009,61988102,and 61971397)the National Key Research and Development Program of China (Grant Nos.2019YFA0307703 and 2018YFB2202500)。
文摘We report the laser-chirp controlled terahertz(THz) wave generation from two-color-laser-induced air plasma.Our experimental results reveal that the THz wave is affected by both the laser energy and chirp,leading to radiation minima that can be quantitatively reconstructed using the linear-dipole-array model.The phase difference between the two colors,determined by the chirp and intensity of the laser,can account for the radiation minima.Furthermore,we observe an asynchronous variation in the generated THz spectrum,which suggests a THz frequency-dependent phase matching between the laser pulse and THz wave.These results highlight the importance of laser chirp during the THz wave generation and demonstrate the possibility of modulating the THz yields and spectrum through chirping the incident laser pulse.This work can provide valuable insights into the mechanism of plasma-based THz wave generation and offer a unique means to control THz emissions.
