HIGHLY EFFICIENT EXCITATION OF OPTICAL NEAR-FIELD ON AN APERTURED FIBER PROBE WITH AN ASYMMETRIC STRUCTURE

We propose and demonstrate a novel method to enhance the near-held opt ical intensity on the apertured probe with its foot removed asymmetric ally by using a focused ion beam, The spatial distribution of the near -field optical intensity on the asymmetric probe was observed by scann ing another sharpened symmetric probe over the aperture. The observed spatial distribution profile was in good agreement with a numerical re sult col-responding to the HE11 mode, Furthermore, compared with the s ymmetric apertured probe. a 10 times enhancement of the near-field opt ical intensity on the asymmetric apertured probe was observed. (C) 199 7 American Institute of Physics.