Structured ultrashort-pulse laser beams, and in particular eigenmodes of the paraxial Helmholtz equation, are currently extensively studied for novel potential applications in various fields, e.g., laser plasma acceleration, attosecond science, and fine micromachining. To extend these prospects further, in the present work we push forward the advancement of such femtosecond structured laser sources into the 2-μm spectral region. Ultrashort-pulse Hermite– and Laguerre–Gaussian laser modes both with a pulse duration around 100 fs are successfully produced from a compact solid-state laser in combination with a simple single-cylindrical-lens converter. The negligible beam astigmatism, the broad optical spectra, and the almost chirp-free pulses emphasize the high reliability of this laser source. This work, as a proof of principle study, paves the way toward few-cycle pulse generation of optical vortices at 2 μm. The presented light source can enable new research in the fields of interaction with organic materials, next generation optical detection, and optical vortex infrared supercontinuum.

中文翻译：

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结构化激光束：朝向2μm飞秒激光旋涡

结构化的超短脉冲激光束，特别是近轴Helmholtz方程的本征模，目前正在广泛研究，以用于各个领域的新潜在应用，例如激光等离子体加速，阿秒科学和精细微加工。为了进一步扩展这些前景，在当前工作中，我们将这种飞秒结构的激光源推进到2μm光谱范围内。紧凑型固态激光器结合简单的单圆柱透镜转换器成功地产生了脉冲持续时间约为100 fs的超短脉冲Hermite-和Laguerre-Gaussian激光模式。可以忽略不计的光束像散，宽光谱和几乎没有chi的脉冲强调了该激光源的高可靠性。这项工作作为原理研究的证明，为朝着2μm的光学涡旋产生几个周期的脉冲铺平了道路。提出的光源可以在与有机材料相互作用，下一代光学检测和光学涡旋红外超连续谱领域进行新的研究。