We carry out the numerical simulations of femtosecond laser propagation with TEMoo mode, TEM10 mode and a beam combining both the modes in fused silica. It is found that the transverse size of plasma zones induced by ...We carry out the numerical simulations of femtosecond laser propagation with TEMoo mode, TEM10 mode and a beam combining both the modes in fused silica. It is found that the transverse size of plasma zones induced by laser pulses with the TEM10 mode is smaller than that induced by the TEM00 mode, while the longitudinal size is almost the same, and the saturated plasma density is higher. The transverse size, the longitudinal size and the ratio of the longitudinal to transverse size, for the beam combining both the modes, all could be reduced at the same time in comparison with the TEM00 mode under the same focusing conditions.展开更多
Temporal evolution of absorption induced by single femtosecond pulse （13Ors, 800nm） with high intensity in LiNbO3 is obtained using the probe shadow imaging technique in order to investigate light-induced electron r...Temporal evolution of absorption induced by single femtosecond pulse （13Ors, 800nm） with high intensity in LiNbO3 is obtained using the probe shadow imaging technique in order to investigate light-induced electron relaxation processes. By saturating the polaron density with a high intensity laser pulse, ultra-fast decay process on picosecond time scale is observed. The decay time constant is about 141 ps and it is attributed to the direct interband electron-hole recombination process.展开更多
Conical double frequency emission is investigated by femtosecond laser pulses at a wavelength of 80Ohm in a DKDP crystal. It is demonstrated that the sum frequency of incident wave and its scattering wave accounts for...Conical double frequency emission is investigated by femtosecond laser pulses at a wavelength of 80Ohm in a DKDP crystal. It is demonstrated that the sum frequency of incident wave and its scattering wave accounts for the conical double frequency emission. The gaps on the conical rings are observed and they are very sensitive to the propagation direction, and thus could be used to detect the small angle deviation of surface direction.展开更多
基金Supported by the National Basic Research Programme of China under Grant No 2006CB806007, the National Natural Science Foundation of China under Grant Nos 10574006, 10634020 and 10521002, and the New Century Excellent Talent （NCET） Project of the Ministry of Education of China.
文摘We carry out the numerical simulations of femtosecond laser propagation with TEMoo mode, TEM10 mode and a beam combining both the modes in fused silica. It is found that the transverse size of plasma zones induced by laser pulses with the TEM10 mode is smaller than that induced by the TEM00 mode, while the longitudinal size is almost the same, and the saturated plasma density is higher. The transverse size, the longitudinal size and the ratio of the longitudinal to transverse size, for the beam combining both the modes, all could be reduced at the same time in comparison with the TEM00 mode under the same focusing conditions.
基金Supported by the National Basic Research Programme of China under Grant No 2006CB806007, the National Natural Science Foundation of China under Grant Nos 10574006, 10634020 and 10521002, and the New Century Excellent Talent Project of the Ministry of Education of China.
文摘Temporal evolution of absorption induced by single femtosecond pulse （13Ors, 800nm） with high intensity in LiNbO3 is obtained using the probe shadow imaging technique in order to investigate light-induced electron relaxation processes. By saturating the polaron density with a high intensity laser pulse, ultra-fast decay process on picosecond time scale is observed. The decay time constant is about 141 ps and it is attributed to the direct interband electron-hole recombination process.
基金Supported by the National Basic Research Program under Grant No 2006CB806007, and the National Natural Science Foundation of China under Grant Nos 10574006, 10634020 and 10821062, and the New Century Excellent Talent Project （NCET） of the Ministry of Education of China
文摘Conical double frequency emission is investigated by femtosecond laser pulses at a wavelength of 80Ohm in a DKDP crystal. It is demonstrated that the sum frequency of incident wave and its scattering wave accounts for the conical double frequency emission. The gaps on the conical rings are observed and they are very sensitive to the propagation direction, and thus could be used to detect the small angle deviation of surface direction.
