Single-fibre surface-enhanced Raman sensors with angled tips

Single-fibre surface-enhanced Raman sensors were prepared by depositing rou gh metal films at the tips of optical fibres, Different deposition techniqu es such as slow evaporation of metal island films and vacuum deposition of metal films over nanoparticles or on pre-roughened surfaces were applied an d compared, The superposition of surface Raman spectra from the tips with R aman spectra of the fibre core made maximum enhancements necessary for the construction of long fibre sensors. The enhancement was improved significan tly by altering the tip geometry, Angled polishing has enhanced the SERS in tensity by up to a factor of 6. The intensity increases monotonically with increase in the angle, reaching its maximum value at the largest prepared a ngle of 40 degrees. Copyright (C) 2000 John Whey & Sons, Ltd.