Summers Adam M, Yu Xiaoming, Wang Xinya, Raoul Maxime, Nelson Josh, Todd Daniel, Zigo Stefan, Lei Shuting, Trallero-Herrero Carlos A
Opt Express. 2017 Feb 6;25(3):1646-1655. doi: 10.1364/OE.25.001646.
We present a compact, simple design for the generation and tuning of both the spot size and effective focal length of Bessel-like beams. In particular, this setup provides an important tool for the use of Bessel-like beams with high-power, femtosecond laser systems. Using a shallow angle axicon in conjunction with a spherical lens, we show that it is possible to focus Bessel-like modes to comparable focal spot sizes to sharp axicons while maintaining a long effective focal length. The resulting focal profiles are characterized in detail using an accurate high dynamic range imaging technique. Quantitatively, we introduce a metric (R) which defines the spot-size containing 80% of the total energy. Our setup overcomes the typical compromise between long working distances and small spot sizes. This is particularly relevant for strong-field physics where most experiments must operate in vacuum.
我们提出了一种紧凑、简单的设计，用于产生和调节类贝塞尔光束的光斑尺寸和有效焦距。特别地，这种装置为在高功率飞秒激光系统中使用类贝塞尔光束提供了一个重要工具。通过将浅角度轴棱锥与球面透镜结合使用，我们表明可以将类贝塞尔模式聚焦到与尖锐轴棱锥相当的焦斑尺寸，同时保持较长的有效焦距。使用精确的高动态范围成像技术对所得的焦斑轮廓进行了详细表征。定量地，我们引入了一个度量（R），它定义了包含总能量80%的光斑尺寸。我们的装置克服了长工作距离和小光斑尺寸之间的典型折衷。这对于强场物理尤其重要，因为大多数实验必须在真空中进行。
