Optical Antenna Properties of Scanning Probe Tips:  Plasmonic Light Scattering, Tip−Sample Coupling, and Near-Field Enhancement

2008 ◽  
Vol 112 (10) ◽  
pp. 3766-3773 ◽  
Author(s):  
Nicolas Behr ◽  
Markus B. Raschke
1997 ◽  
Vol 11 (21) ◽  
pp. 2465-2510 ◽  
Author(s):  
Igor I. Smolyaninov

Recent development of novel scanning probe techniques such as Scanning Tunneling Microscopy (STM), Atomic Force Microscopy (AFM), and Near-Field Optical Microscopy (NFOM) has opened new ways to study local field distribution of surface electromagnetic waves. A lot of experimental efforts have been concentrated on the study of surface plasmons (SP). Different techniques allow to excite and probe SPs with wavelengths from 1 nm down to the optical range along its entire dispersion curve. Large number of phenomena have been studied directly, such as SP scattering by individual defects, strong and weak localization of SP, SP induced local field enhancement, light emission from the tunneling junction, etc. Scanning probe techniques allow not only topography and field mapping but also surface modification and lithography on the nanometer scale. Combination of these features in the same experimental setup proved to be extremely useful in SP studies. For example, some prototype two dimensional optical elements able to control SP propagation have been demonstrated.


Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 2097-2105
Author(s):  
Xiaozhuo Qi ◽  
Tsz Wing Lo ◽  
Di Liu ◽  
Lantian Feng ◽  
Yang Chen ◽  
...  

AbstractPlasmonic nanocavities comprised of metal film-coupled nanoparticles have emerged as a versatile nanophotonic platform benefiting from their ultrasmall mode volume and large Purcell factors. In the weak-coupling regime, the particle-film gap thickness affects the photoluminescence (PL) of quantum emitters sandwiched therein. Here, we investigated the Purcell effect-enhanced PL of monolayer MoS2 inserted in the gap of a gold nanoparticle (AuNP)–alumina (Al2O3)–gold film (Au Film) structure. Under confocal illumination by a 532 nm CW laser, we observed a 7-fold PL peak intensity enhancement for the cavity-sandwiched MoS2 at an optimal Al2O3 thickness of 5 nm, corresponding to a local PL enhancement of ∼350 by normalizing the actual illumination area to the cavity’s effective near-field enhancement area. Full-wave simulations reveal a counterintuitive fact that radiation enhancement comes from the non-central area of the cavity rather than the cavity center. By scanning an electric dipole across the nanocavity, we obtained an average radiation enhancement factor of about 65 for an Al2O3 spacer thickness of 4 nm, agreeing well with the experimental thickness and indicating further PL enhancement optimization. Our results indicate the importance of configuration optimization, emitter location and excitation condition when using such plasmonic nanocavities to modulate the radiation properties of quantum emitters.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nantao Li ◽  
Taylor D. Canady ◽  
Qinglan Huang ◽  
Xing Wang ◽  
Glenn A. Fried ◽  
...  

AbstractInterferometric scattering microscopy is increasingly employed in biomedical research owing to its extraordinary capability of detecting nano-objects individually through their intrinsic elastic scattering. To significantly improve the signal-to-noise ratio without increasing illumination intensity, we developed photonic resonator interferometric scattering microscopy (PRISM) in which a dielectric photonic crystal (PC) resonator is utilized as the sample substrate. The scattered light is amplified by the PC through resonant near-field enhancement, which then interferes with the <1% transmitted light to create a large intensity contrast. Importantly, the scattered photons assume the wavevectors delineated by PC’s photonic band structure, resulting in the ability to utilize a non-immersion objective without significant loss at illumination density as low as 25 W cm−2. An analytical model of the scattering process is discussed, followed by demonstration of virus and protein detection. The results showcase the promise of nanophotonic surfaces in the development of resonance-enhanced interferometric microscopies.


2001 ◽  
Author(s):  
Wei Chih Lin ◽  
Jun D. Su ◽  
Ming C. Tsai ◽  
Din Ping Tsai ◽  
Nien H. Lu ◽  
...  

2016 ◽  
Vol 2 (10) ◽  
pp. e1601006 ◽  
Author(s):  
Eric A. Muller ◽  
Benjamin Pollard ◽  
Hans A. Bechtel ◽  
Peter van Blerkom ◽  
Markus B. Raschke

Molecular solids and polymers can form low-symmetry crystal structures that exhibit anisotropic electron and ion mobility in engineered devices or biological systems. The distribution of molecular orientation and disorder then controls the macroscopic material response, yet it is difficult to image with conventional techniques on the nanoscale. We demonstrated a new form of optical nanocrystallography that combines scattering-type scanning near-field optical microscopy with both optical antenna and tip-selective infrared vibrational spectroscopy. From the symmetry-selective probing of molecular bond orientation with nanometer spatial resolution, we determined crystalline phases and orientation in aggregates and films of the organic electronic material perylenetetracarboxylic dianhydride. Mapping disorder within and between individual nanoscale domains, the correlative hybrid imaging of nanoscale heterogeneity provides insight into defect formation and propagation during growth in functional molecular solids.


Nanomaterials ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 536 ◽  
Author(s):  
Ignacio Falcón Casas ◽  
Wolfgang Kautek

Optical methods in nanolithography have been traditionally limited by Abbe’s diffraction limit. One method able to overcome this barrier is apertureless scanning probe lithography assisted by laser. This technique has demonstrated surface nanostructuring below the diffraction limit. In this study, we demonstrate how a femtosecond Yb-doped fiber laser oscillator running at high repetition rate of 46 MHz and a pulse duration of 150 fs can serve as the laser source for near-field nanolithography. Subwavelength features were generated on the surface of gold films down to a linewidth of 10 nm. The near-field enhancement in this apertureless scanning probe lithography setup could be determined experimentally for the first time. Simulations were in good agreement with the experiments. This result supports near-field tip-enhancement as the major physical mechanisms responsible for the nanostructuring.


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