We describe a self calibrating optical technique that allows to perform absolute measurements of scattering cross sections for the light scattered at extremely small angles. Very good performances are obtained by using a very simple optical layout similar to that used for the schlieren method, a technique traditionally used for mapping local refraction index changes. The scattered intensity distribution is recovered by a statistical analysis of the random interference of the light scattered in a half-plane of the scattering wave vectors and the main transmitted beam. High quality data can be obtained by proper statistical accumulation of scattered intensity frames, and the static stray light contributions can be eliminated rigorously. The potentialities of the method are tested in a scattering experiment from non equilibrium fluctuations during a free diffusion experiment. Contributions of light scattered from length scales as long as Lambda=1 mm can be accurately determined.
Understanding the relationship between visual-angle and eye-angle for reliable determination of the field-of-view in ultra-wide field fundus photography
Ultra-low-loss tapered optical fibers with minimal lengths
我们设计并制造了具有最小长度的超低损耗锥形光纤（TOF）。我们首先优化的火炬扫描长度的变化，使用火焰刷的方法制造的TOF与锥角，满足绝热标准。因此，我们制造的TOF的最佳形状和比较他们的传输TOF与一个恒定的锥角和TOF的指数形状。对于具有最佳形状的TOF测量的最高透射率超过99.7%，总TOF长度仅为23 mm，而对于63 mm TOF长度，具有2 mrad的恒定锥角的TOF达到99.6%的透射率。
Ultrawide-angle diffraction-limited 2D beam steering via hybrid integrated metasurface-photonic circuit
Massachusetts Institute of Technology（麻省理工学院）；Pi Inc.（2Pi公司）；Singapore-MIT Alliance for Research and Technology (SMART)（新加坡-麻省理工学院研究与技术联盟）；University of Maryland, College Park（马里兰大学帕克分校）；NASA Langley Research Center（美国国家航空航天局兰利研究中心）；Korea Advanced Institute of Science and Technology（韩国科学技术院）
Neural Étendue Expander for Ultra-Wide-Angle High-Fidelity Holographic Display
Princeton University（普林斯顿大学）；Reality Labs Research, Meta（Meta 现实实验室研究部）；Pohang University of Science and Technology (POSTECH)（浦项科技大学）；King Abdullah University of Science and Technology (KAUST)（阿卜杜拉国王科技大学）
Probing the formation of femtosecond laser-induced periodic surface structures on silica films by ultrafast small-angle X-ray scattering
University of Duisburg-Essen（杜伊斯堡-埃森大学）；Bentley Systems, Incorporated（宾利系统公司）；European XFEL（欧洲自由电子激光实验室）；Bundesanstalt für Materialforschung und -prüfung (BAM)（联邦材料研究与测试研究所）；Warsaw University of Technology（华沙理工大学）；Institute of Physics, Polish Academy of Sciences（波兰科学院物理研究所）；SLAC National Accelerator Laboratory（斯坦福直线加速器中心）
Electromagnetic Field Tapering in the High-Roughness Substrates Coated by a Thin Film of Manganese: A Lithography-Free Approach to Ultra-Broadband, Wide-Angle, UV to FIR Perfect Absorption
Extreme Ultraviolet Time- and Angle-Resolved Photoemission Spectroscopy with 21.5 meV Resolution using High-Order Harmonic Generation from a Turn-Key Yb:KGW Amplifier
表征和控制量子材料的电子性质需要在动量空间的大区域上直接测量非平衡电子能带结构。在这里，我们展示了一个实验装置的时间和角度分辨的光电子能谱使用高次谐波探测脉冲产生的一个强大的，中等高功率（20 W）Yb：KGW放大器与可调重复频率在50和150 kHz之间。通过驱动高次谐波产生（HHG）的基本1025 nm的激光脉冲的二次谐波，我们表明，在21.8 eV的光子能量的单谐波探测脉冲可以有效地隔离，而不使用单色器。在50 kHz下，靶上光子通量可以达到5 x 10^10光子/秒，并且测量的时间分辨率为320 fs。Yb驱动的HHG源的相对较长的脉冲持续时间使我们能够达到21.5 meV的优异能量分辨率，这是通过在150 kHz的较高重复率下使用1.5 x 10^8光子/秒的低光子通量抑制空间电荷展宽来实现的。通过测量拓扑半金属ZrSiS和拓扑绝缘体Sb 2-xGdxTe 3的设置的能力证明。
