KEYWORDS: Near field, Near field optics, Near field scanning optical microscopy, Silver, Heterodyning, Atomic force microscopy, Surface roughness, Surface plasmons, Interferometry, Optical microscopy
To study nano-scale optical local-field phenomena, an apertureless near-field scanning optical microscope (aNSOM) is
an important tool. Herein, an aNSOM has been developed and is utilized for observing the local surface plasmon
resonance, wave propagation, and nano-antenna enhancement of nanoprisms. The developed aNSOM, based on a
commercial atomic force microscope, is integrated with homodyne and heterodyne interferometric techniques to detect
the near-field amplitude and phase of nanostructures. With the help of mechanical system designs, different illumination
direction s and detections for different applications can be achieved.
A two-dimensional (2D) surface plasmon (SP)-enhanced optical trapping system based on a single high numerical
aperture objective has been developed. The system can be utilized to trap dielectric particles and simultaneously
provide imaging. The 40-fold electric field enhancement, and hence strong 2D trapping force distribution with SP
excitation through a gold film with a thickness of 45 nm in the near infrared region, was analyzed. The strong trapping
force and high-resolution trapping image of nanoparticles can be concurrently achieved via the same high NA objective.
The developed SP-enhanced trapping system was successfully applied to efficiently trap dielectric particles with a size
down to 350 nm on a cover slip surface and allows for real-time imaging observation. Also, in order to further increase
the penetration depth and the electric field of the evanescent wave, a coupled-waveguide surface plasmon resonance
configuration consisting of a five-layer structure of Bk7/Au/SiO2/Au/H2O for two-dimensional optical trapping has
been developed. Theoretical analysis shows that the maximum enhancement of the local electric field intensity is about
60-fold while the penetration depth is about 1 μm at the resonance angle. The trapped and aligned dielectric single layer
particles were spread over a large area with a reduction in feature size to form a hexagonally close-packed (HCP)
pattern on a cover slip surface. The HCP pattern has the potential for well-ordered 2D nanosphere lithography.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.