Pabon D O, Ledesma S A, Quinteiro G F, Capeluto M G
Appl Opt. 2017 Oct 10;56(29):8048-8054. doi: 10.1364/AO.56.008048.
We present a compact design to generate and test optical-vortex beams with possible applications in the extreme ultraviolet (EUV) region of the electromagnetic spectrum. The device consists of a diffractive mask where both the beam with orbital angular momentum and the reference wavefront to test its phase are generated. In order to show that the proposal would work in the EUV, simulations and proof-of-principle experiments were performed, using typical parameters for EUV holography scaled to visible wavelengths. As the simplest case, we consider the well-known Laguerre-Gaussian (LG)-like beams, which have a single vortex in the propagation axis. To further test the versatility of the device, we consider Mathieu beams, more complex structured beams that may contain several vortices. In the experiment, a spatial light modulator was used to display the mask. As examples, we show the results for a LG-like beam with topological charge ℓ=1 and Mathieu beams with topological charge ℓ=2 and ellipticity q=2. These results show the potential of the device to generate a variety of beam shapes at EUV wavelengths.
我们提出了一种紧凑的设计，用于产生和测试光学涡旋光束，其在电磁频谱的极紫外（EUV）区域可能具有应用价值。该装置由一个衍射掩模组成，在该掩模中既产生具有轨道角动量的光束，也产生用于测试其相位的参考波前。为了证明该方案在EUV中可行，我们进行了模拟和原理验证实验，使用了按比例缩放到可见光波长的EUV全息术的典型参数。作为最简单的情况，我们考虑了众所周知的类拉盖尔 - 高斯（LG）光束，其在传播轴上有单个涡旋。为了进一步测试该装置的通用性，我们考虑了马修光束，这是一种可能包含多个涡旋的结构更复杂的光束。在实验中，使用空间光调制器来显示掩模。作为示例，我们展示了拓扑电荷ℓ = 1的类LG光束以及拓扑电荷ℓ = 2和椭圆率q = 2的马修光束的结果。这些结果表明了该装置在EUV波长下产生各种光束形状的潜力。
