title: Ultra-sensitive surface absorption spectroscopy using sub-wavelength diameter optical fibers.
abstract: 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.
authors: F
authors: F
authors: Warken
authors: E
authors: E
authors: Vetsch
authors: D
authors: D
authors: Meschede
authors: M
authors: M
authors: Sokolowski
authors: A
authors: A
authors: Rauschenbeutel