Ultra-sensitive surface absorption spectroscopy using sub-wavelength diameter optical fibers

Author(s): F. Warken, E. Vetsch, D. Meschede, M. Sokolowski, A. Rauschenbeutel

Journal: Optics Express

Volume: 15

Page(s): 11952-11958

Year: 2007

DOI Number: 10.1364/OE.15.011952

Link: Link to publication


The guided modes of sub-wavelength diameter air-clad optical fibers exhibit a pronounced evanescent field. The absorption of particles on the fiber surface is therefore readily detected via the fiber transmission. We show that the resulting absorption for a given surface coverage can be orders of magnitude higher than for conventional surface spectroscopy. As a demonstration, we present measurements on sub-monolayers of 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) molecules at ambient conditions, revealing the agglomeration dynamics on a second to minutes timescale.

Note: http://arxiv.org/abs/cond-mat/0701264

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