标题： 使用三种不同频的激光诱导等离子体产生太赫兹辐射 显示英文标题

标题： Laser-induced plasma generation of terahertz radiation using three incommensurate wavelengths

摘要： 我们展示了通过聚焦具有三个不同波长的超快激光脉冲形成等离子体来产生太赫兹辐射。 三种颜色包括800 nm以及来自光学参量放大器的可变红外信号和闲频输出。 当所有三种颜色都存在时，可以生成稳定的太赫兹辐射，峰值到峰值的场强约为200 kV/cm，并且具有相对较宽且平滑的光谱，扩展到6 THz，且对信号和闲频红外波长的选择（在1300-2000 nm范围内）没有明显依赖性。 我们确认确实需要三种颜色，并对产生的太赫兹的偏振特性进行了评论，其中一些特性难以用在描述双色等离子体太赫兹辐射方面已取得成功的等离子体电流模型来解释。 显示英文摘要

摘要： We present the generation of THz radiation by focusing ultrafast laser pulses with three incommensurate wavelengths to form a plasma. The three colors include 800 nm and the variable IR signal and idler outputs from an optical parametric amplifier. Stable THz is generated when all three colors are present, with a peak-to-peak field strength of ~200 kV/cm and a relatively broad, smooth spectrum extending out to 6 THz, without any strong dependence on the selection of signal and idler IR wavelengths (in the range from 1300-2000 nm). We confirm that 3 colors are indeed needed, and comment on the polarization characteristics of the generated THz, some of which are challenging to explain with plasma current models that have had success in describing two-color plasma THz generation.