研究目的
Investigating the plasma formation and relaxation dynamics in fused silica driven by femtosecond short-wavelength infrared laser pulses to understand the intensity-dependent relaxation time.
研究成果
The study demonstrates an intensity-dependent relaxation time of the electron-hole plasma in fused silica, attributed to vibrational activation of the medium. This finding extends the understanding of laser-matter interaction into the short-wavelength infrared spectral domain and suggests a refinement of theoretical models to include intensity-dependent relaxation phenomena.
研究不足
The study is limited to the bulk of fused silica and does not account for surface effects or propagation effects in the material. The intensity values in simulations are significantly above experimental values due to the exclusion of nonlinear effects like self-focusing.
1：Experimental Design and Method Selection:
The study uses a time-resolved transmission measurement combined with a cross-phase modulation measurement to isolate plasma formation and relaxation dynamics in fused silica.
2：Sample Selection and Data Sources:
A fused silica sample of 500 μm thickness is used, with the pump laser pulse focused to a spot size of 33 μm and the probe laser pulse to 75 μm.
3：List of Experimental Equipment and Materials:
Ti:sapphire laser system, optical parametric amplifier, photodiode, NIR-spectrometer, fused silica sample.
4：Experimental Procedures and Operational Workflow:
The pump and probe laser pulses are temporally and spatially overlapped inside the fused silica sample, with the probe laser pulse's transmission and spectrum analyzed as a function of pump-probe delay.
5：Data Analysis Methods:
The relaxation of quasifree carriers is approximated by a single exponential decay time, and the energy coupled into the electron-hole plasma is estimated using a condition for energy conservation.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
