Department of Physics and Astronomy, UCLA, Los Angeles, California 90095, USA.
Advanced Light Source Division, LBNL, Berkeley, California 94720, USA.
Phys Rev Lett. 2013 Feb 15;110(7):074801. doi: 10.1103/PhysRevLett.110.074801. Epub 2013 Feb 11.
We experimentally investigate surface-plasmon assisted photoemission to enhance the efficiency of metallic photocathodes for high-brightness electron sources. A nanohole array-based copper surface was designed to exhibit a plasmonic response at 800 nm, fabricated using the focused ion beam milling technique, optically characterized and tested as a photocathode in a high power radio frequency photoinjector. Because of the larger absorption and localization of the optical field intensity, the charge yield observed under ultrashort laser pulse illumination is increased by more than 100 times compared to a flat surface. We also present the first beam characterization results (intrinsic emittance and bunch length) from a nanostructured photocathode.
我们通过实验研究了表面等离激元辅助光发射，以提高用于高亮度电子源的金属光电阴极的效率。设计了一种基于纳米孔阵列的铜表面，使其在 800nm 处呈现等离子体响应，使用聚焦离子束铣削技术制造，经过光学特性表征，并在高功率射频光电离器中用作光电阴极进行了测试。由于光场强度的更大吸收和局域化，与平面相比，在超短激光脉冲照射下观察到的电荷产额增加了 100 多倍。我们还介绍了来自纳米结构光电阴极的第一个束特性（固有发射度和束长）结果。
