Giant near-field optical enhancement with subnanometer tip-sample distance sensitivity

• Published in: Quantum Electronics and Laser Science Conference (QELS 2000). Technical Digest. Postconference Edition. TOPS Vol.40 (IEEE Cat. No.00CH37089) pp. 61 - 62
• Main Authors: Martinez, O.E., Bragas, A.V., Lester, M.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 2000
• Subjects: Apertures; Dielectric materials; Gold; Large Hadron Collider; Optical imaging; Optical sensors; Optical surface waves; Optimized production technology; Pattern analysis; Tunneling
• ISBN: 1557526087; 9781557526083
• ISSN: 1094-5695

Summary form only given. In a recent paper, A.V. Bragas et al. (1998) have shown a giant optical field enhancement (more than 1000) at the tip-sample junction of a scanning tunneling microscope. The magnitude of the field enhancement obtained is larger than expected from abundant calculation performed for different tip-sample geometries. In this work it is shown that when the metallic tip is approached to a sample to subnanometer distances, and it is shone with light, the field enhancement at the tip is increased by a resonant mechanism, yielding light scattering signals extremely sensitive to the tip-sample distance. Experimental results indicate subnanometer sensitivity, and a model is given consistent with the results.