Nanoplasmonic Structures in Optical Fibers

Plasmonic crystal cavity on single-mode optical fiber end facet for label-free biosensing

“…This corresponds to DL = 3.5 × 10 -6 RIU, which is 1~2 orders of magnitude better than reported for modified-end multimode fiber SPR devices. 2,4,22,23 Here it is important to note that, the sharp SPR spectrum not only gives a high FOM, but as importantly allows us to use SLD instead of the commonly used halogen lamp, the former having a much narrower bandwidth than the latter. Using SMF-coupled SLD enables us to couple much more light into the SMF, and consequently to obtain a higher signal to noise ratio (SNR).…”

“…Among them, single mode fiber (SMF) end-facet devices are the most adaptable for a variety of sample configurations including microfluidics, microtiter plates and in vivo access, and are highly desired for disease diagnosis and drug discovery applications. 1,2 However, up to date, all high-performance SMF label-free biosensors are based upon sensing devices on the fibers' sidewalls, and work in a fiber-sensing area-fiber transmission manner. [2][3][4] In spite of the fact that the sidewall devices are limited to have large size sensing areas, there have been an amount of biosensing applications and optical investigations of them in recent years.…”

“…1,2 However, up to date, all high-performance SMF label-free biosensors are based upon sensing devices on the fibers' sidewalls, and work in a fiber-sensing area-fiber transmission manner. [2][3][4] In spite of the fact that the sidewall devices are limited to have large size sensing areas, there have been an amount of biosensing applications and optical investigations of them in recent years. [5][6][7][8][9][10] Chemically etched SMF taper sensors have also been demonstrated in a free-space radiation manner.…”

“…In the efforts to integrate surface plasmon resonance (SPR) devices on the planar end facets of optical fibers, people have made periodic metallic nanostructures to couple the fiber guided lightwaves to surface plasmons, such as nanohole arrays, nanoparticle arrays and gratings. 2,[13][14][15][16][17][18][19][20][21] However, all the reported devices on SMF end facets have very broad and shallow resonance spectra to date, and consequently they are mainly employed for surface enhanced Raman spectroscopy. This results from the numerical aperture (NA) of fibers and the periodic coupling structures used.…”

Photonic crystal fiber based plasmonic sensors

“…Metal nanoparticles may also be implemented by controlling their size during fabrication to form a thin and uniform coating in the PCF. Quite few studies been done on metal nanoparticle-modified PCF in Surface-Enhanced Raman Scattering (SERS) [147][148][149][150]. Moreover, SPR-like sensing using surface waves is not exclusive for the visible-near-IR spectral ranges.…”