已为您找到该学者20条结果 成果回收站
【期刊论文】Ultraviolet-infrared femtosecond laser-induced damage in fused silica and CaF2 crystals
贾天卿, T.Q. Jia, H.X. Chen, M. Huang, and F.L. Zhao, X.X. Li, S.Z. Xu, H.Y. Sun, D.H. Feng, C.B. Li, X.F. Wang, R.X. Li, and Z.Z. Xu, X.K. He and H. Kuroda
,-0001,():
-1年11月30日
The damage in fused silica and CaF2 crystals induced by wavelength tunable femtosecond lasers is studied. The threshold fluence is observed to increase rapidly with laser wavelength λ in the region of 250-800nm, while it is nearly a constant for 800<λ<2000nm. The ultrafast electronic excitation is also studied by a pump and probe method. The reflectivity increases rapidly in the latter half of pump pulse, which supports that impact ionization plays an important role in the generation of conduction band electrons (CBEs). We study the CBEs absorption via subconduction-band sub-CB transition, and develop a coupled avalanche model. Our results indicate that the CBEs absorption via sub-CB transition plays an important role in the damage in dielectrics irradiated by the visible and near ultraviolet femtosecond lasers. Our theory explains well the experiments.
-
76浏览
-
0点赞
-
0收藏
-
0分享
-
115下载
-
0
-
引用
【期刊论文】Mechanisms of femtosecond laser-induced damage in magnesium fluoride
贾天卿, Haiyi Suna, *, Tianqing Jiaa, b, Chengbin Lia, Xiaoxi Lia, Shizhen Xua, Donghai Fenga, Xiaofeng Wanga, Xiaochun Gea, Zhizhan Xua
Solid State Communications 141 (2007) 127-131,-0001,():
-1年11月30日
We studied the single-shot damage in magnesium fluoride irradiated by 800 nm femtosecond (fs) laser. The dependence of damage thresholds on the laser pulse durations from 60 to 750 fs was measured. The pump-probe measurements were carried out to investigate the time-resolved electronic excitation processes. A coupled dynamic model was applied to study the microprocesses in the interaction between fs laser and magnesium fluoride. The results indicate that both multiphoton ionization and avalanche ionization play important roles in the femtosecond laser-induced damage in MgF2.
A., Magnesium fluoride, D., Damage mechanisms, E., Femtosecond laser, E., Pump–probe measurements
-
64浏览
-
0点赞
-
0收藏
-
0分享
-
147下载
-
0
-
引用
【期刊论文】Mechanisms of femtosecond laser-induced breakdown and damage in MgO
贾天卿, S.Z. Xu a, *, T.Q. Jia a, b, H.Y. Sun a, C.B. Li a, X.X. Li a, D.H. Feng a, J.R. Qiu a, Z.Z. Xu a
Optics Communications 259 (2006)274-280,-0001,():
-1年11月30日
Single-shot laser damage threshold of MgO for 40-986 fs, 800 nm laser pulses is reported. The pump-probe measurements with femtosecond pulses were carried out to investigate the time-resolved electronic excitation processes. A theoretical model including conduction band electrons (CBE) production and laser energy deposition was applied to discuss the roles of multiphoton ionization (MPI) and avalanche ionization in femtosecond laser-induced dielectric breakdown. The results indicate that avalanche ionization plays the dominant role in the femtosecond laser-induced breakdown in MgO near the damage threshold.
Avalanche ionization, Laser-induced breakdown, Femtosecond laser, Time-resolved dynamics, MgO
-
57浏览
-
0点赞
-
0收藏
-
0分享
-
130下载
-
0
-
引用
贾天卿, D.H. Fenga, Z.Z. Xu, T.Q. Jia, X.X. Li, C.B. Li, H.Y. Sun, and S.Z. Xu
Eur. Phys. J. B44, 15-20 (2005),-0001,():
-1年11月30日
Within the framework of second-order Rayleigh-Schrödinger perturbation theory, the polaronic correction to the first excited state energy of an electron in an quantum dot with anisotropic parabolic confinements is presented. Compared with isotropic confinements, anisotropic confinements will make the degeneracy of the excited states to be totally or partly lifted. On the basis of a three-dimensional Fröhlich’s Hamiltonian with anisotropic confinements, the first excited state properties in two-dimensional quantum dots as well as quantum wells and wires can also be easily obtained by taking special limits. Calculations show that the first excited polaronic effect can be considerable in small quantum dots.
-
56浏览
-
0点赞
-
0收藏
-
0分享
-
73下载
-
0
-
引用
【期刊论文】Catalytic synthesis and photoluminescence of needle-shaped 3C-SiC nanowires
贾天卿, D.H. Fenga, *, T.Q. Jiaa, X.X. Lia, Z.Z. Xua, J. Chenb, S.Z. Dengb, Z.S. Wub, N.S. Xub
Solid State Communications 128(2003)295-297,-0001,():
-1年11月30日
Needle-shaped 3C-SiC nanowires were grown from commercially available SiC powders in a thermal evaporation process with iron as catalyst. A strong broad photoluminescence peak located around 450 nm was observed at room temperature, which may be ascribed to quantum size effects of nanomaterials. Needle-shaped 3C-SiC nanowires may have great potential applications such as blue-green light-emitting diodes and display devices.
A., Nanostructures, A., Semiconductors, D., Optical properties
-
55浏览
-
0点赞
-
0收藏
-
0分享
-
73下载
-
0
-
引用