@article{lim_wirth_bravo_schuck_hallen_2019, title={Large Available Volume Particles for Enhanced Deep UV Local Raman Sensing}, volume={11086}, ISSN={["1996-756X"]}, DOI={10.1117/12.2529434}, abstractNote={The combination of resonance Raman with deep UV excitation, DUVRR, gives greater selectivity and eliminates background fluorescence, enabling sensitive detection of UV absorbing nucleotide bases and amino acids. We demonstrate this combination with our 3D nanopore structure design. Resonance Raman is specific to a molecule absorbing at the excitation, while plasmon resonance of a small, shape-, index- and size- tuned metal dramatically increases the electric field strength in the active region. The 3D nanostructure exploits nanopores that retain the advantages of small-gap antennas but increases the ease of fabrication, availability, and detection volume compared to conventional plasmon-based designs, such as gaps between two particles, by being inherently single particle, with edge enhancement open to diffusion, and by possessing a large number of pores per particle. We show the large local field enhancement (hot spots) of the pores. Comparisons with an Al and silica coated/uncoated microsphere template with/without nanopores clearly show a significant blue shift of the 280 nm peak to (the more useful) 265 nm, in the presence of a hollow sphere with nanopores. Raman measurement of Tryptophan on an aluminum nanopore structure with excitation from our tunable OPO system in the visible and deep UV region indicate visible excitation causes more fluorescence and is less specific for the tryptophan, even displaying a Raman peak at the silicon substrate, while the deep-UV Raman spectra, at an energy close to the nanopore resonance, shows no substrate signal and peaks with close correlation to the known tryptophan vibrations.}, journal={UV AND HIGHER ENERGY PHOTONICS: FROM MATERIALS TO APPLICATIONS 2019}, author={Lim, Shuang Fang and Wirth, Janina and Bravo, Angel Fernandez and Schuck, Peter James and Hallen, Hans D.}, year={2019} }
 @article{wirth_green_o'connor_lim_2017, title={Enhancement of upconverted fluorescence by interference layers}, volume={13}, number={6}, journal={Small (Weinheim An Der Bergstrasse, Germany)}, author={Wirth, J. and Green, K. K. and O'Connor, M. and Lim, S. F.}, year={2017} }
 @article{wirth_hallen_lim_2017, title={Influence of Gold Metallodielectric Partial-Shell Geometrical Irregularities on Dark Plasmon Resonances}, volume={121}, ISSN={["1932-7447"]}, url={http://dx.doi.org/10.1021/acs.jpcc.7b05060}, DOI={10.1021/acs.jpcc.7b05060}, abstractNote={The geometric asymmetry of real, fabricated gold partial shells leads to orientation and gold partial coverage dependent local fields and scattering. We illustrate this with single-particle measurements and finite element calculations. In particular, we show that the position and number of well-defined protrusions on the edge of a partial shell qualitatively change the spectra. The metallic protrusions result in geometrical asymmetry, which leads to excitation of the optically dark quadrupole mode as a function of incident light excitation and polarization. The far-field scattering peaks result from the bright dipole resonance with contribution from the dark resonance in the presence of the partial-shell surface protrusions. With more dark modes, the overall scattered intensity decreases, reflecting the energy trapped in the local electric fields of the dark modes, until it ultimately dissipates in the metal.}, number={29}, journal={JOURNAL OF PHYSICAL CHEMISTRY C}, publisher={American Chemical Society (ACS)}, author={Wirth, Janina and Hallen, Hans and Lim, Shuang Fang}, year={2017}, month={Jul}, pages={15937–15942} }
 @article{green_wirth_lim_2017, title={Nanoplasmonic upconverting nanoparticles as orientation sensors for single particle microscopy}, volume={7}, journal={Scientific Reports}, author={Green, K. K. and Wirth, J. and Lim, S. F.}, year={2017} }
 @article{green_wirth_lim_2016, title={Optical investigation of gold shell enhanced 25 nm diameter upconverted fluorescence emission}, volume={27}, number={13}, journal={Nanotechnology}, author={Green, K. and Wirth, J. and Lim, S. F.}, year={2016} }
 @inproceedings{green_wirth_o'connor_lim_2015, title={Multifunctional diagnostic, nanothermometer, and photothermal nano-devices}, volume={9584}, booktitle={Ultrafast nonlinear imaging and spectroscopy iii}, author={Green, K. and Wirth, J. and O'Connor, M. and Lim, S. F.}, year={2015} }