Surface-plasmon field-enhanced multiphoton photoelectric emission from metal films.
Surface-plasmon field-enhanced multiphoton photoelectric emission from metal films.
复制标题
金属薄膜的表面等离子体场增强多光子光电发射。
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
Fischer
中科院分区：
文献类型：
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作者：
Tsang;Srinivasan;Fischer
研究了Ag、Au、Cu和Al薄膜的表面等离子体介导的多光子光电发射，实验采用Kretchmann衰减全内反射几何结构，激发源为未放大的飞秒碰撞脉冲锁模环形激光器。对比通过照射在金属表面上的激光获得的电子发射，电子产率增加了几个数量级，具有相当高的量子效率，观察到当光子耦合到这些薄膜的表面等离子体激元模式。虽然光子吸收达到其最大值时，反射率表现出深的最小值在表面等离子体共振角，它被发现，最大的电子产率发生在一个稍微不同的角度比反射率下降。这些测量的结果有利于使用菲涅耳方程的场密度计算。然而，利用这种非线性光电效应测量的电子时间分布的宽度未能显示与高阶非线性相称的变窄。
We report a study of surface-plasmon-mediated multiphoton photoelectric emission from thin films of Ag, Au, Cu, and Al. The experiments were performed in the Kretchmann attenuated-total-internal reflection geometry while the excitation source was an unamplified femtosecond colliding-pulse mode-locked ring laser. Contrast to the electron emission obtained by irradiating the laser on a metal surface, electron yield increases by several orders of magnitude with fairly high quantum efficiency, is observed when photons are coupled to the surface-plasmon modes of these films. Although the photon absorption reaches its maximum when the reflectivity exhibits a deep minimum at the surface-plasmon resonance angle, it is found that the maximum electron yield occurs at a slightly different angle than the reflectivity dip. The results of these measurements favor the field-density calculations using the Fresnel equations. The width of the electron temporal profile, measured utilizing this nonlinear photoelectric effect, however, fails to show the narrowing commensurate with the higher-order nonlinearity.