Husakou A, Herrmann J
Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy, Max-Born-Strasse 2a, D-12489 Germany.
Phys Rev Lett. 2006 Jan 13;96(1):013902. doi: 10.1103/PhysRevLett.96.013902. Epub 2006 Jan 3.
We show that a scanning light beam can be focused below the diffraction limit without the control of moving near-field elements using the combination of two main components: a light-controlled saturable absorber, which creates seed evanescent components from the beam, and a layer of negative-refraction material, which amplifies the evanescent waves. Focusing to spots with a FWHM in the range of 0.2-0.3 lambda is predicted. For slightly off-resonant input beams, an intensity-dependent phase shift leads to smaller spots.
我们表明，利用两个主要组件的组合，扫描光束可以在不控制移动近场元件的情况下聚焦到衍射极限以下：一个光控可饱和吸收体，它从光束中产生种子倏逝分量；以及一层负折射材料，它放大倏逝波。预计可以聚焦到半高宽在0.2 - 0.3λ范围内的光斑。对于略微失谐的输入光束，强度依赖的相移会导致更小的光斑。
