AVS 46th International Symposium
    Nanometer-scale Science and Technology Division Tuesday Sessions
       Session NS-TuA

Paper NS-TuA10
Imaging the Near-field Intensity Gradients with a Tapping-mode Near-field Scanning Optical Microscope

Tuesday, October 26, 1999, 5:00 pm, Room 612

Session: Innovative Nanoscale Measurements
Presenter: D.P. Tsai, National Chung Cheng University, Taiwan
Authors: D.P. Tsai, National Chung Cheng University, Taiwan
C.W. Yang, National Chung Cheng University, Taiwan
Correspondent: Click to Email
A tapping-mode near-field scanning optical microscope system using a non-optical tuning fork method has been developed recently. One of the advantage of this new method is that tapping of the near-field optical fiber probe can provide the measurements of the near-field intensity gradients at different heights vertically. Based on the modulation of the near-field optical fiber probe, near-field intensity gradients were used as a new contrast mechanism of the NSOM. The imaging of the near-field field optical intensity gradients have been successfully applied on the study of both the propagating and evanescent field intensity. The propagating field with a constant intensity shows an image of zero gradients. The evanescent intensity gradients of the configurations of total international reflection or surface plasmons, on the other hand, indicate the local optical properties of the photon-matter interactions. Imaging contrast of the near-field optical intensity gradients of a focused spot on the clear cover glass slip and the gold-coated cover glass slip will be shown. Property of the local optical interactions of the gold thin film in near field was discerned. Results demonstrate the novelty of the imaging contrast of the near-field intensity gradients.