Experimental Setup
An electromagnetic field which interacts with metallic materials might be modified in a way that locally confined fields exist in the surrounding of the metallic structure. We study such optical nearfields by an unconventional method: the enhanced field is used for local ablation of the silicon substrate below the metallic structure by a femtosecond laser pulse. The ablation region, which reflects the local field can then be imaged with an atomic force microscope (AFM).
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Electron microscopy of ablated material which show how the nearfield pattern depends on the polarization of the material. -
A comparison the FTDT-simulation shows the expected nearfield distribution.