Surface plasmon resonances of optical antenna atomic force microscope tips
Yanshu Zou, Paul Steinvurzel, Tian Yang, Kenneth B Crozier
Applied Physics Letters | AMER INST PHYSICS | Published : 2009
A method for fabricating optical antennas on atomic force microscope probes using focused ion beam modification is described. We numerically demonstrate that these optical antenna probes provide a large near field intensity enhancement when illuminated at their resonant wavelengths. We experimentally measure the plasmon resonant wavelengths of probes with various lengths. Both simulation and experiment indicate that the resonant wavelength redshifts with increasing antenna length. We anticipate that the optical antenna tips could be used for mapping the field distributions of nanophotonic devices or for high spatial resolution spectroscopy. © 2009 American Institute of Physics.
This work is supported by the Microsystems Technology Office (MTO) of the Defense Advanced Research Projects Agency (DARPA) and by the National Science Foundation (NSF). Fabrication work was carried out at the Harvard Center for Nanoscale Systems, which is supported by the NSF. The authors thank Nanfang Yu and Eric Kort for fruitful discussions and Richard Schalek for assistance in doing FIB.