Focused ion beam fabrication of metallic nanostructures on end faces of optical fibers for chemical sensing applications

Focused ion beam (FIB) fabrication of fiber optic sensors, mainly chemical sensors, which are based on plasmonics-active nanostructures formed on the cleaved tips of optical fibers, is reported. The nanostructures fabricated included nanoholes in optically thick metallic films as well as metallic nanopillars and nanorods. The sensing mechanism is based on detecting shifts in surface plasmon resonances (SPRs) associated with nanoholes in metallic films and localized SPRs of metallic nanopillars and nanorods, when the refractive index of the medium surrounding the nanostructures is changed. These sensors can be employed for the detection of chemical agents in air as well as liquid media surrounding the sensors. FIB milling was employed to fabricate ordered arrays of nanoholes in optically thick (100–240nm) metallic films deposited on cleaved end faces of multimode, four-mode, and single-mode optical fibers. Separately, metallic nanorods and nanopillars were formed by first depositing a metallic (gold or sil...

[1]  Adam D. McFarland,et al.  Single Silver Nanoparticles as Real-Time Optical Sensors with Zeptomole Sensitivity , 2003 .

[2]  Henri Lezec,et al.  Diffracted evanescent wave model for enhanced and suppressed optical transmission through subwavelength hole arrays. , 2004, Optics express.

[3]  W. Barnes,et al.  Surface plasmon subwavelength optics , 2003, Nature.

[4]  Radan Slavik,et al.  Single-mode optical fiber surface plasmon resonance sensor , 1999 .

[5]  Thomas W. Ebbesen,et al.  The role of localized surface plasmon modes in the enhanced transmission of periodic subwavelength apertures , 2005 .

[6]  T. Ebbesen,et al.  Molecule–Surface Plasmon Interactions in Hole Arrays: Enhanced Absorption, Refractive Index Changes, and All‐Optical Switching , 2006 .

[7]  A. Haes,et al.  A unified view of propagating and localized surface plasmon resonance biosensors , 2004, Analytical and bioanalytical chemistry.

[8]  E. Palik.  Handbook of Optical Constants of Solids , 1997 .

[9]  Anuj Dhawan,et al.  Plasmon resonances of gold nanoparticles incorporated inside an optical fibre matrix , 2006, Nanotechnology.

[10]  David R. Smith,et al.  Local Refractive Index Dependence of Plasmon Resonance Spectra from Individual Nanoparticles , 2003 .

[11]  H. Bethe.  Theory of Diffraction by Small Holes , 1944 .

[12]  H. Raether.  Surface Plasmons on Smooth and Rough Surfaces and on Gratings , 1988 .

[13]  A. Dhawan,et al.  Plasmonic Structures Based on Subwavelength Apertures for Chemical and Biological Sensing Applications , 2008, IEEE Sensors Journal.