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数值研究了掺氧化镁铌酸锂晶体中高强度近红外飞秒激光脉冲的线性电光效应。研究结果发现,当在垂直于晶体光轴的方向上施加一定外电场使光脉冲实现最强的电光耦合时,输出脉宽在正常色散区随着输入光强的增大而增大;而在较强反常色散区,输出脉宽随着输入光强增大而减小。对中心波长λ0=1.6335μm的光脉冲,线性电光效应可使输出脉宽产生压缩。当输入脉宽T0=5fs和光强I0=20GW/cm2时,最小输出脉宽为输入脉宽T0的0.76倍。而当T0>5fs时,最小输出脉宽小于0.76T0。若在晶体光轴方向上施加另一个电场对光脉冲进行相位调制,则最小输出脉宽的光脉冲中心波长发生蓝移或红移;随着外电场的增大,蓝移或红移量相应增大。
The linear electro-optic effect of high intensity near-infrared femtosecond laser pulses in magnesium oxide-doped lithium niobate crystals was numerically investigated. The results show that when a certain external electric field is applied in the direction perpendicular to the optical axis of the crystal to achieve the strongest electro-optic coupling of the optical pulse, the output pulse width increases with the input light intensity in the normal dispersion region; Strong anomalous dispersion area, the output pulse width decreases with increasing input intensity. For the light pulse with central wavelength λ0 = 1.6335μm, the linear electro-optic effect can compress the output pulse width. When the input pulse width T0 = 5fs and light intensity I0 = 20GW / cm2, the minimum output pulse width is 0.76 times the input pulse width T0. When T0> 5fs, the minimum output pulse width is less than 0.76T0. If another electric field is applied to the optical axis of the crystal to phase-modulate the optical pulse, the central wavelength of the optical pulse with the minimum output pulse width is blue-shifted or red-shifted. As the external electric field increases, the blue shift or the red shift corresponds to Increase.