类表面等离激元在速度匹配下加速带电粒子

Acceleration of charged particles by surface-plasmons in terms of velocity matching

提出了一种利用类表面等离激元(SSP)来加速电子的新机制。通过把金属表面设计成梯度型凹槽结构,SSP和电子可以同时获得沿表面方向的加速,这种结构可以提高SSP和电子的相互作用的效率和距离。数值模拟结果显示,通过控制凹槽结构来实现类SSP相速度与电子速度近似匹配(QVM)时,电子的加速效果最好,当电子沿纵向运动0.055 m后,其相对论因子会超过21。

A mechanism for electron acceleration by spoof surface plasmons（ SSP） is proposed.By using a specially designed metal surface with a gradient structural size,the SSP mode and electron can be accelerated simultaneously along the surface.The electron or charged particle can be efficiently accelerated by controlling the groove structure which allows the phase velocity of the SSP mode to be manipulated.Our results show that the electron acceleration effect is optimal when the phase velocity of the SSP mode is quasi-velocity matched（ QVM） with the electron velocity.As an example,the final relativistic factor γ can exceed 21 after the electron travels forwards by0.055 m,leading to more efficient electron acceleration.